The invention relates to a multi-chamber plate, a filling system and a method for filling a multi-chamber plate with a sample fluid. Multi-chamber plates and methods according to the invention may preferably be used in the field of in-vitro diagnostics (IVD), for example for analyzing samples of a human body, like blood, urine, saliva, interstitial fluid or other body fluids.
In the field of IVD, multi-chamber plates have-become a widely used tool. Thus, various geometries for chamber plates and methods for filling them are known, like described for example in
US 2007/0134710 A1. A method and a device for simultaneously testing a sample for the presence, absence, and/or amounts of one or more a plurality of selected analytes are introduced. The device includes a substrate which defines a sample-distribution network having a sample inlet, one or more detection chambers, and channel means providing a dead-end fluid connection between each of the chambers and the inlet. The sample is drawn into the network and distributed to the detection chambers by vacuum below atmospheric pressure action.
US 2007/0014695 A1 discloses systems and methods for multiple analyte detection including a system for distribution of a biological sample that includes a substrate, wherein the substrate includes a plurality of sample chambers, a sample introduction channel for each sample chamber, and a venting channel for each sample chamber. The system may further include a preloaded reagent contained in each sample chamber and configured nucleic acid analysis of a biological sample that enters the substrate and a sealing instrument configured to be placed in contact with the substrate to seal each sample chamber from flowing out of each sample chamber.
European
patent applicationEP 1 977 829 A1 discloses a device for performing multiple analyses in parallel with a liquid sample. The device comprises reaction sections connected to a venting system comprising venting channels, wherein the capillary force of the reaction sections to the sample is greater than the capillary force of the venting system and the venting system is designed for venting several reaction systems in common.
In
EP 1 936 383 A1 a testing device is disclosed having a transparent molded body which includes: a storage chamber for injecting/holding a liquid sample; a reaction chamber for causing a reaction of the sample; a receiving chamber for sucking and receiving the sample, with the storage chamber and the reaction chamber being in communication with each other via a distributing flow path, and the reaction chamber and the receiving chamber being in communication with each other via a sucking flow path; and a liquid reservoir between the reaction chamber and the receiving chamber. The reaction chambers may be filled with a reagent for example in advance.
DE 10 2004 063 438 A1 discloses a microfluidic plate with at least one sample intake chamber for a sample liquid, at least one-distribution channel connected with the at least one sample intake chamber. Each sample intake chamber sprawls at least one distribution channel. The plate furthermore has at least one reaction chamber, in which one air venting channel branching from the at least one distribution channel may lead. The plate has at least one venting opening per reaction chamber. The plate may be filled with reagents. The publication furthermore discloses methods for inducing motion of the sample liquid: electrokinetic, pressure and capillary forces.
In
US 7,560,073 B1 a sample support is disclosed, comprising at least one sampling receiving chamber for a sample liquid, and a distributor channel for sample liquid connected to said at least one receiving chamber, with at least one such distributor channel extending from each sample receiving chamber. The sample support further comprises at least one reaction chamber entered by an inflow channel branched off said at least one distributor channel, and a venting opening for each reaction chamber. Each distributor channel and each inflow channel are dimensioned to have the liquid transport through the distributor and inflow channels affected by capillary forces.
United States patent application publication
US 2008/0213755 A1 describes a device and a method for real-time amplification and detection of target nucleic acids contained in a large number of biological samples. The device can comprise a substrate and an optically transparent cover, wherein the substrate can comprise a first surface, at least one sample receiving chamber, a distributor channel, at least one reaction chamber, and a vent for each reaction chamber. In this patent the device is optimized for transport of a liquid sample into the at least one reaction chamber enabled by mainly capillary action, although the possibilities of using centrifugal forces, gravity and/or pressure are mentioned. It is further described that the vents can be made hydrophobic to allow gas to pass through while preventing liquid from passing through.
A further example for a multi-chamber plate is disclosed in
WO 2006/116616 A2, wherein a sample chamber is filled by either spinning the substrate to provide centrifugal force or by sizing sample introductory channels to provide capillary force and aspirating the sample through the vent channels or by providing positive pressure to the sample. The system may further include a preloaded reagent contained in each sample chamber and the chambers may be connected to a vent chamber closed by a liquid-impermeable membrane.
Another example of filling a chamber by centripetally manipulating liquids is described in
US 2006/0288762 A1. In this example, a gas outlet is fluidly coupled to a testing chamber to allow egress of gas out of the testing chamber. The gas outlet has an elevation that is higher than an elevation of a liquid inlet, perpendicular to the centrifugal force, such that, as the testing is rotated, the gas is expelled out of the testing chamber through the gas outlet, thereby reducing or preventing a presence of gas bubbles in the liquid.
United States patent application publication
US 2006/0189000 A1 discloses a device in which first feeder conduits form first feeder conduit angles with a main conduit that are less than 90° and second feeder conduits form second feeder conduit angles with the main conduit that are less than 90°. Furthermore, a serial relationship between process chambers located along main conduits is described in this patent application. It is mentioned that reagents may be contained in a wax or other substance within each of the process chambers to prevent removal of the reagents during distribution of the sample material.
Various patent documents describe methods and structures to facilitate the filling of chamber plates and to avoid the formation of bubbles.
US 2007/0280856 A1 describes for example that at least some of the sample chambers may include a physical modification configured to control the movement of the meniscus so as to control bubble formation within the sample chambers.
Furthermore, methods are known by which a reagent release after the filling process may be controlled in order to prevent removal of the reagent during the filling process.
US 2006/0189000 A1 discloses that reagents may be contained in a wax or another substance within each of the process chambers to prevent removal of the reagents during filling. A similar method is described in
US 2009/0042256 A1, in which a thermally fusible material which is solid at room temperature encapsulates the reagent. Furthermore, a method is described, in which a reagent is contained by a reagent well, which is sealed with a film, or has an openable and closable cap, so that the reagent can be injected. In United States patent
US 6,669,683 B2, microchip delivery devices are provided that control both the rate and time of release of molecules. In this example, molecules are contained in a reservoir. The molecules are released from the reservoir by rupturing a reservoir cap, which is positioned on the reservoir over the molecules. An embodiment is described, where the reservoir cap ruptures due to mechanical stress caused by a thermal expansion, vaporization, phase change, or by a thermally driven reaction. Alternatively, the thermal trigger can be a temperature change. In another embodiment of this patent, the device includes reservoir caps that rupture due to expansion, contraction, or phase change of the cap material in response to the temperature change. In yet another embodiment, the device includes reservoir caps or release systems that become more permeable to the molecules in response to a temperature change. The reservoir cap preferably is a thin film of a material having a yield-or tensile strength beyond which the material fails by fracture or some other form of mechanical failure. Alternatively, the reservoir cap could be made of a material that loses structural integrity when it undergoes a phase change in response to a change in temperature.
In
EP 1 740 721 B1, a process for DNA amplification by PCR (polymerase chain reaction) is described, where water-soluble reagents are firstly covered with a layer of a water-insoluble medium, which may be paraffin. The DNA to be amplified is supplied in an aqueous solvent. The covering effect of the water-insoluble medium is subsequently negated, so that the water-soluble reagents dissolve in the aqueous solvent, after which the PCR thermocycling reactions can start.
EP 2 311 565 A1 relates to a device with closable fluid paths. In this application, a sealing method is disclosed, in which a polymer is used which fills at least a part of a channel system in order to seal chambers.
The chamber plates and methods for filling them with a sample fluid, as disclosed by the prior art, however, exhibit some significant disadvantages and shortcomings. Thus, major technical challenges during filling of the chambers via a distribution system, reside in a potential cross-contamination between chambers and, further, in a potential incomplete filling of the chambers. Filling of chamber plates, is an important aspect for all applications in IVD, in which chamber plates are to be used for fluid handling. For PCR, chemicals are spotted in each chamber and dried. When the chambers are filled, these chemicals are dissolved and may become mobile. These dissolved chemicals from one chamber may be transported into other chambers. This cross-contamination may destroy a selective, specific PCR in each chamber.
Further, during filling of the chambers, air inside the chamber plate must be vented. Incomplete filling or trapping of air bubbles may be detrimental to the filling and detection process. Since air is compressible, trapped air will expand when e.g. a centrifuge stops, due to surface tension effects or thermal influences. This expansion may lead to unwanted flow effects, contamination and empty chambers. Furthermore, a partially filled chamber might lead to a variation in a dry reagent concentration and air bubbles might lead to a detection error, for example in analyses with air bubbles in an optically detection path.
It is therefore an objective of the present invention to provide a multi-chamber plate, a filling system and a method for filling a multi-chamber plate with a sample fluid, which at least partially overcome the shortcomings of devices and methods known from prior art. Specifically, devices and methods for bubble-free filling of chambers out of a central intake reservoir should be provided. Further, a filling procedure is needed that avoids both removal of pre-spotted reagents from the chambers and cross-contamination between the chambers.
In a first aspect of the present invention, a multi-chamber plate is disclosed. The multi-chamber plate may preferably but not necessarily comprise a flat element having a plurality of chambers, which preferably but not necessarily are located in one and the same plane. However, other shapes are possible. Examples are fluidic chips being partially or integrally made of glass, plastics, semiconductor materials, ceramic materials or metallic materials, having a fluid structure. The fluidic structure may e.g. be made by etching, molding, machining, laser engraving, lithographic techniques or by other methods. The whole multi-chamber plate or parts of it may be made of transparent materials, but may also be partially or completely opaque.
The multi-chamber plate according to this invention can preferably be used for analytical purposes. The multi-chamber plate may be used in the field of IVD, as described above. The multi-chamber plate has a plurality of chambers and a channel system for filling the chambers with at least one sample fluid. The sample fluid may be or may comprise any fluid medium, i.e. at least one liquid medium and/or at least one gaseous medium. Preferably, the sample fluid may comprise all kinds of body fluids, like blood, interstitial fluid, urine or saliva, or parts thereof. Preferably all elements of the multi-chamber plate, such as the chambers and the channel system, may be located in one and the same plane, preferably in a plane parallel to one or more surfaces of the multi-chamber plate. Other embodiments of a channel system may also be possible, like channel systems which extend over several planes.
The multi-chamber plate has a proximal end and a distal end, wherein a radial direction is defined from the proximal end to the distal end. A centrifugal force is applicable parallel to the radial direction. In the context of this invention, a centrifugal force may comprise any acceleration forces, except forces caused by pressure or vacuum or capillary forces. Thus, centrifugal forces may comprise, for example, an accelerating force due to one or more pseudo forces, such as a Coriolis force and/or, preferably, a centrifugal force. Alternatively or-additionally, the centrifugal force may also comprise a-gravitational force. A gravitational force may also point in a direction different from the direction of the centrifugal force.
Within the present invention, the centrifugal force may act on all masses contained in the multi-chamber plate basically unidirectionally, whereas other types of forces, such as capillary forces or pressure forces, typically may act in directions which depend on the geometry of the multi-chamber plate. Nevertheless, capillary forces and/or pressure forces additionally may be applicable in the context of this invention. The centrifugal force may be, for example, generated by spinning or rotating at least a part of the multi-chamber plate, such as by using a centrifuge.
The channel system comprises at least one application site for applying the sample fluid to the channel system. Furthermore, the chambers each have at least one inlet opening and at least one outlet opening being separate from the inlet opening. The inlet opening and the outlet opening are positioned on a proximal side of the chambers, i.e. a side of the chambers facing the proximal end of the multi-chamber plate. Thus, a connection from the center of the chamber, for example, the center of volume or the center of gravity of the chamber, to the middle of the inlet opening or to the outlet opening has a directional component towards the proximal end. The chambers are fillable through the inlet openings with the sample fluid driven by the centrifugal force. The filling process may solely be driven by centrifugal forces, or, additionally, may be driven by one or more other forces, such as pressure forces and/or capillary forces.
Preferably, the inlet opening and the outlet opening are located in close proximity. Thus, preferably, the inlet opening and the outlet opening of the chambers, preferably of all chambers, may be located such that, a connection between the center of the chamber and the inlet opening (such as the center of the inlet opening) and a connection between the center of the chamber and the outlet opening (e.g. the center of the outlet opening) enclose an angle of no more than 120°, preferably of no more than 90°, more preferably of no more than 60° and most preferably of no more than 50°. Preferably, after one chamber, e.g. one well, or more chambers are filled through the inlet opening, preferably completely, a flow of the sample fluid may be directed through the outlet opening without completely flowing through, e.g. without completely crossing, the filled chamber, due to the close proximity of the inlet opening and the outlet opening. Preferably, the sample fluid enters the chamber through the inlet opening having a first direction of flow and may leave the chamber through the outlet opening having a second direction of flow, wherein the first direction of flow and the second direction of flow preferably form a small angle of no more than 120°, preferably no more than 90°, more preferably of no more than 60° and most preferably of no more than 50°.
The chambers are vented through the outlet openings. At least one reagent is located in the chambers. The reagent may be adapted to perform at least one chemical reaction when the sample fluid or a specific component of the sample fluid is present and/or to change at least one detectable property when the sample fluid or a component thereof, such as an analyte to be detected, is present. The reagent preferably comprises a test chemical or a PCR mixture, for example an enzyme, a primer or a buffer, or other chemical or biological substances. The reagent preferably may be spotted and/or dried, e.g. the reagent may comprise at least one dry chemical. The reagents may be accessible for the sample fluid from the interior of the chambers. The reagent also may be stored in the interior of the chamber, the chamber walls, encapsulated in a dissolvable gel. All methods for the implementation of reagents well-known from prior art may also be used.
Preferably, the reagent is located below the inlet opening and the outlet opening of the respective chamber containing the reagent. Thus, the reagent preferably is located further towards the distal end of the multi-chamber plate than the respective inlet opening and the respective outlet opening of the chamber.
Preferably, the at least one reagent is located at a distance from the inlet opening and the outlet opening of the chamber, preferably in all chambers. Thus, preferably, the reagent is located at a distance from the inlet opening and from the outlet opening which exceeds 10% of the diameter or equivalent diameter of the chamber (measured in the plane of the multi-chamber plate). More preferably, the distance exceeds 30% of the diameter or equivalent diameter, and most preferably exceeds 50% of the diameter or equivalent diameter.
The channel system has at least one main feeding line and at least one main venting line. As used herein, a main line, such as the at least one main feeding line and/or the at least one main venting line, is a line connected to at least two chambers, preferably three or more chambers. Several main lines may be provided, e.g. in parallel.
The at least one main venting line and the at least one main feeding line at least partially are separate from each other. Thus, the main feeding line is at least partially separate from the main venting line and/or the main venting line is at least partially separate from the at least one main feeding line. As used herein, the term "line A being at least partially separate from line B" refers to the fact that at least one-segment of line A is not part of line B. Thus, as used herein, the main venting line being at least partially separate from the main feeding line refers to the fact that the main venting line comprises at least one segment which is not part of the main feeding line. Further, as used herein, the main feeding line being at least partially separate from the main venting line refers to the fact that the main feeding line comprises at least one segment which is not part of the main venting line. The term the main venting line and the main feeding line at least partially being separate from each other refers to the fact that the main venting line comprises at least one segment which is not part of the main feeding line and/or the main feeding line comprises at least one segment which is not part of the main venting line.
The main feeding line may be dedicated for filling, e.g. for filling with a clean sample fluid, and the main venting line may be dedicated for venting, e.g. for venting of gas, potentially polluted sample fluid and/or aerosols. The main feeding line and the main venting line are fluidly connected with each other. Thus, the main venting line is in fluid communication with the main feeding line. As used herein, the term being fluidly connected refers to a setup in which a fluid exchange between the elements being fluidly connected is possible.
The inlet openings, preferably all of the inlet openings or at least a plurality of the inlet openings, are connected to the main feeding line at inlet channel junctions, wherein the outlet openings, preferably all of the outlet openings, at least a plurality of the outlet openings, are connected to the main venting line at outlet channel junctions. The inlet channel junctions are located further towards the distal end than the respective outlet channel junctions. The respective outlet channel junction belongs to the same chamber as the inlet channel junction. This way, it may be guaranteed that the main venting line will be closed by the increasing fluid level after the chamber is filled through the main feeding line.
The inlet openings, the outlet openings, the inlet channel junctions and the outlet channel junctions are arranged such that, during the filling with the sample fluid, a venting of each chamber is possible until the respective chamber is completely filled with the sample fluid. This time sequence of filling and venting may be achieved by an appropriate arrangement of the inlet openings, the outlet openings, the inlet channel junctions and the outlet channel junctions with regard to the proximal end and the distal end of the multi-chamber plate, as the skilled person will recognize fromFigures 7A to 7E and the description below. Thus, as for each chamber, the inlet opening may be arranged closer towards the distal end than the respective outlet opening, and the inlet channel junction may be arranged closer towards the distal end than the respective outlet channel junction. Further examples of technical realization will be given in more detail below.
In order to evaluate if this venting possibility up to complete filling exists for each of the chambers, an experimental setup containing an optical detection system detecting the filling status and the venting status of the chambers and the time development of this filling/venting status may be applied. Thus, the filling and venting of the chambers during a filling process, such as by using a centrifuge, may be detected by using an optical high-speed camera and/or a camera synchronized with the centrifuge. Thereby, a sequence of images indicating the filling and/or venting status of the chambers may be generated during the filling process, which allows for an evaluation of a filling and/or venting schedule. For the optical setup, an imaging wavelength might be used, wherein the multi-chamber plate or chamber walls of this multi-chamber plate at least partially are transparent for the imaging wavelength, wherein the imaging wavelength at least partially may be absorbed and/or scattered by the sample fluid, in order to provide images having sufficient contrast for detecting the filling status and/or the venting status.
The term venting may refer to an exhaust of the multi-chamber plate, preferably of each chamber. Venting may include for example an exhaust of air, e.g. air bubbles, and/or other gases and/or aerosols. The term completely filled may refer to a complete filling of at least one chamber, preferably a filling of the respective chamber with the sample fluid with a percentage of more than 80 % of the volume of the chamber, e.g. more than 95 %, preferably about 100 %. Therein, gas contents of the sample fluid itself may be neglected, such as gas dissolved or fineley dispersed in the sample fluid and, thus, invisible by optical inspection methods.
Preferably, after completely filling the respective chamber with the sample fluid, the chamber and/or the respective inlet channel junction and/or the respective inlet opening may be closed by the sample fluid, preferably in such way, that a stream of the sample fluid through the chamber at least partially may be suppressed.
According to the present invention and as disclosed in further detail below, the setup of the multi-chamber plate according to the present invention may guarantee an order of filling of the chambers which is adapted to avoid a flush-out of the at least one reagent contained in the chambers during the filling procedure. Similarly, a cross-contamination of the chambers may be avoided, since the chambers may contain different reagents.
The performance of avoidance or reduction of cross-contamination between the chambers, e.g. wells, may be analyzed by spotting at least one of the chambers, e.g. half of the number of chambers, with at least one fluorescent dry substance, e.g. at least one fluorescent dry reagent, while preferably leaving neighboring chambers empty and/or without the fluorescent dry substance. After filling the chambers virtually no fluorescent signal may be measured in the empty chambers and/or channels. The measurement e.g. may be performed by the above mentioned optical setup.
The main venting line and the main feeding line are fluidly connected. Thus, the main feeding line is in fluid communication with the main venting line and/or vice versa.
The main venting line and the main feeding line are connected at at least one connection point, which may allow for a fluidic connection between the main venting line and the main feeding line. This at least one connection point is located close to the distal end of the multi-chamber plate. Thus, the main venting line and the main feeding line are connected at the distal end of the multi-chamber plate. Herein, the term "at the distal end" may refer to an arrangement in which the connection point is located closer towards the distal end of the multi-chamber plate than any of the inlet channel junctions and any of the outlet channel junctions of the main feeding line and the main venting line, respectively. The main venting line and the main feeding line may be at least partially identical, e.g. at least a part of the main venting line may act as the main feeding line and/or at least a part of the main venting line may act as the main feeding line.
The channel system may be arranged such that the chambers located further towards the distal end are filled before chambers located further towards the proximal end when the centrifugal force is applied. At least one chamber located further towards the distal end is filled before at least one chamber located further towards the proximal end.
In order to realize this time sequence of filling, the inlet openings, the inlet channel junctions and the main feeding line may be arranged such that, firstly, the centrifugal force drives the sample fluid, e.g. a sample liquid, to a position closer towards the distal end of the multi-chamber plate than any of the inlet channel junctions, before the sample fluid is guided, against the direction of the centrifugal force, to the inlet channel junctions. To do so, a curve may be provided in the main feeding channel. Subsequently, at least one first inlet channel junction being located further towards the distal end of the multi-channel plate may be reached by the sample fluid before at least one second inlet channel junction being located further towards the proximal end than the first inlet channel junction is reached, by appropriate arrangement of the inlet channel junctions and/or outlet channel junctions along the main feeing line, most preferably before the respective outlet channel junction, e.g. with the venting channel, is reached. Further details of potential design realizations will be given in more detail below.
In order to evaluate if the above-mentioned order of filling of the chambers is given or not, an experimental setup containing an optical detection system detecting the filling status of the chambers and the time development of this filling status may be applied, which may be similar to the experimental setup discussed above. Thus, the filling of the chambers during a filling process, such as by using a centrifuge, may be detected by using an optical high-speed camera and/or a camera synchronized with the centrifuge. Thereby, a sequence of images indicating the filling status of the chambers may be generated during the filling process, which allows for an evaluation of the filling schedule. For the optical setup, an imaging wavelength might be used, wherein the multi-chamber plate or chamber walls of this multi-chamber plate at least partially are transparent for the imaging wavelength, wherein the imaging wavelength at least partially may be absorbed and/or scattered by the sample fluid, in order to provide images having sufficient contrast for detecting the filling status. Preferably, the point of time for filling is a function monotonously decreasing with the radial direction. This filling procedure preferably applies to all chambers of the plate, i.e. any chamber being positioned further inwardly is filled after any other chamber which is positioned further outwardly. Thereby, a centrifugally induced differential pressure filling procedure may be facilitated.
Venting channels may be connected to the outlet openings, wherein the venting channels are arranged such that gas, such as air bubbles, and/or dust, which may be pushed out from the chambers through the venting channels has at least one velocity component anti-parallel to the radial direction. A venting channel connects an outlet opening to an outlet channel junction.
One or more feeding channels may be connected to the inlet openings. Thus, the feeding channels are arranged such that sample fluid entering the chambers through the feeding channels has at least one velocity component parallel to the radial direction. At least one feeding channel may connect an inlet opening to at least one inlet channel junction. The distance between a position along the venting/feeding channel and the proximal end is preferably monotonically decreasing starting at the outlet/inlet opening. This may prevent the formation or storage of gas bubbles, which might occur in channel systems in which the distance between a position along the venting/feeding channel and the proximal end is non-monotonically decreasing starting at the outlet/inlet opening, e.g. in siphon-shaped venting/feeding channel designs.
The outlet openings may have at least one tapered region. Within the tapered region, the diameter as a function of the distance from the center of the chamber is decreasing. A tapered region may e.g. be a region with a cone shape, a rounded tapered shape, a shape of a frustum of a pyramid, preferably a region shaped like a funnel with a decreasing diameter towards the proximal end.
The channel system may be designed such that the sample fluid applied to the application site, driven by the centrifugal force, passes at least one first feeding line segment being directed in radial direction, before passing a second feeding line segment being directed in counter-radial direction and entering the chambers from the second feeding line segment. In this context, the term (counter-) radial direction may include tolerable deviations from an anti-parallel or parallel orientation with regard to the radial direction, such as deviations not exceeding 20°, preferably not exceeding 10° and most preferably not exceeding 5°. The first feeding line segment and/or the second feeding line segment may also be directed in a direction which has a component perpendicular to the radial direction.
In order to evaluate if this order of passing of the sample fluid is given or not, an experimental setup containing an optical detection system detecting the filling status of the multi-chamber plate and the time development of this filling status may be applied, which may be similar or identical to the experimental setup discussed above. Thus, the filling of the chambers during a filling process, such as by using a centrifuge, may be detected by using an optical high-speed camera and/or a camera synchronized with the centrifuge.
Preferably, the channel system may at least be partially designed to have one of a U-shape, a W-shape and a V-shape.
The reagent may be separated from the sample fluid entering the chambers by at least one releasable barrier. Various embodiments for separations of the reagent and the sample fluid are part of prior art and are described above. The at least one releasable barrier preferably may comprise one or more of the following: a mechanically breakable barrier; a dissolvable barrier; a thermally breakable barrier; a chemically breakable barrier; a photo-chemically breakable barrier.
The channel system may at least have one intake reservoir being connected to the sample application site and being adapted to hold a supply of the sample fluid before feeding the sample fluid into the chambers.
The channel system may have at least one waste reservoir which is adapted to hold excess sample fluid after filling of the chambers.
The channel system may have at least one decant channel, preferably for overload protection of the channel system and/or to prevent discharging sample fluid out of the multi-chamber plate, and subsequent contamination of the multi-chamber plate and/or the environment. The decant channel may ensure complete filling of the chambers, e.g. the wells. As used herein, the term decant channel refers to a channel and/or channel system and/or reservoir which are adapted to collect and/or receive and/or gather excess sample fluid. The decant channel may be adapted to channel away and/or dispose of excess sample fluid. The decant channel may further be adapted to provide an overload protection of at least part of the channel system and/or the chambers and/or one or more of the lines (e.g. the main venting line and/or the main feeding line) of the multi-chamber plate. Furthermore, the overload protection may ensure a stable and/or defined fluid level to prevent undesirable flow effects, e.g. a flow-back of sample fluid into the intake reservoir due to capillary forces. Stable and/or defined fluid levels may imply meniscuses which are always at the same position. The positions of the meniscuses may be fixed by designing the channel system. The decant channel preferably has at least one bypass channel bypassing a main feeding line and/or a main venting line.
The channel system may have at least one fluid restrictor device adapted for controlling a flow of the sample fluid through at least part of the channel system. As used herein, the term fluid restrictor device refers to a device adapted to restrict the flow of a liquid through a line, such as the flow of the sample fluid through the channel system or parts thereof. The fluid restrictor device preferably may be selected from: a narrowed passage; a valve, preferably a geometric valve; a throttle.
In a further aspect of the present invention, a filling system, comprising at least one multi-chamber plate as described above, is disclosed. The filling system further comprises at least one centrifuge. The centrifuge is a device to generate a centrifugal force, to exposure a centrifugal force on the multi-chamber plate and/or on the sample fluid. The centrifuge is charged with the at least one multi-chamber plate. More than one multi-chamber plate may be present. Preferably the centrifuge may be charged with two multi-chamber plates. The filling system is adapted to fill the at least one multi-chamber plate with at least one sample fluid, driven by the centrifugal force generated by the centrifuge.
The centrifuge may comprise one or more receptacles for receiving and, preferably, for positioning and holding the at least one multi-chamber plate during centrifugation. Thus, one or more brackets and/or other types of fixing elements may be contained in the centrifuge.
The at least one sample fluid may be applied to the at least one multi-chamber plate before, after or during charging the centrifuge with the multi-chamber plate.
The centrifuge is arranged to put the multi-chamber plate in rotation, preferably around at least one, preferably one, rotation axis. The rotation axis may be an axis around which at least a part of the multi-chamber plate may rotate, wherein the at least one part preferably contains the above-mentioned at least one receptacle. Preferably, the rotation axis is a fixed axes. Preferably, the rotation axis is arranged such that the whole multi-chamber plate may rotate around the rotation axis during centrifugation.
Preferably, as outlined above, the multi-chamber plate may be fixed at the centrifuge, e.g. the multi-chamber plate may be reversibly fixed at the centrifuge, e.g. by at least one bracket or another type of receptacle. Preferably the multi-chamber plate may be fixed, e.g. with the bracket, at the centrifuge at the proximal end of the multi-chamber plate. Preferably, at least during centrifugation, the distal end is located further away from the rotation axis than the proximal end, e.g. to generate a centrifugal force acting parallel to the radial direction, preferably pointing to the distal end of the multi-chamber plate. The centrifugal force may be added with the gravitational force to an effective force. The centrifugal force or the effective force act on the multi-chamber plate, preferably on the sample fluid. Preferably, the sample fluid is pushed and/or filled into the multi-chamber plate, preferably into the chambers, by these forces.
The centrifuge may further comprise at least one control system. The control system is a device which is adapted to control and/or to drive the filling system and/or the centrifuge. The control system preferably comprises at least one computer and/or at least one electrical connector and/or at least one electrical line and/or at least one interface and/or at least one display and/or at least one user interface, e.g. at least one switch, e.g. for switching on or switching off the filling system and/or the centrifuge. The control system further may comprise at least one tuner for stepless or stepwise changing of the rotation velocity and/or the direction of the rotation and/or the strength of the centrifugal force induced by the centrifuge. The centrifuge further may comprise at least one actuator, e.g. at least one engine, preferably an electrical engine, and/or at least one hand-driven actuator. The actuator may be a device to bring at least a part of the centrifuge into rotation. The actuator may be connected with the control system.
Further, the filling system may comprise at least one device for cooling and/or heating the sample fluid and/or to control the temperature of the sample fluid, e.g. at least one heater and/or at least one cooler and/or at least one thermometer.
As mentioned above, the filling system also may comprise at least one optical detection system, such as an optical detection system comprising at least one high-speed camera and/or at least one camera synchronized with the centrifuge for recording at least one image or at least one sequence of images indicating the filling and/or venting status of the chambers during the filling process, which may allow for an evaluation of a filling and/or venting schedule. For further details, reference may be made to the description above. The filling status and/or the venting status may be controlled and/or used, preferably by the control system and/or the filling system. The optical detection system and the control system may be connected, e.g. by at least one interface. The optical detection system also may be used for detecting optical properties of the sample fluid, e.g. the color and/or a intensity, specifically a fluorescence intensity, e.g. for analysis, e.g. after and/or before and/or during at least one reaction between the sample fluid and the reagent.
In a further aspect of the present invention, a method for filling a multi-chamber plate with at least one sample fluid is disclosed. The method may preferably be performed by using a multi-chamber plate according to one or more of the embodiments disclosed above. The multi-chamber plate has a plurality of chambers and a channel system for filling the chambers with sample fluid. The chambers each have at least one inlet opening and at least one outlet opening being separate from the inlet opening. The multi-chamber plate has a proximal end and a distal end. A radial direction is defined from the proximal end to the distal end, wherein a centrifugal force, as defined above, is applied at least essentially parallel, for example with an angle of smaller than +/- 20°, preferably an angle smaller +/- 10°, specifically an angle smaller +/- 5° and most preferably with an angle of 0° between the radial direction and the centrifugal force, to the radial direction. Both the inlet opening and the outlet opening are positioned on a proximal side. The sample fluid is applied to at least one sample application site of the channel system, wherein at least one reagent, defined above, is located in the chambers. The reagent is separated from the sample fluid during filling of the chambers by at least one releasable barrier, wherein the barrier is released after the chambers have been filled with the sample fluid. The chambers are filled from at least one main feeding line and are vented into at least one main venting line, wherein the main venting line is separate from the main feeding line. The inlet openings are connected to the main feeding line at inlet channel junctions. The outlet openings are connected to the main venting line at outlet channel junctions. The inlet channel junctions are located further towards the distal end than the respective outlet channel junctions. The chambers are filled at least with the sample fluid. The filling is at least partially driven by the centrifugal force. The chambers are vented through the outlet openings in a direction having at least one directional component towards the proximal end. During the filling with the sample fluid, each chamber is vented until the respective chamber is completely filled with the sample fluid.
In the method for filling a multi-chamber plate, the multi-chamber plate as described above and/or the filling system as described above may be used.
Chambers being located further towards the distal end may be filled before chambers being located further towards the proximal end.
The filling of the chambers through the inlet openings may take place having at least one directional component towards the distal end.
The sample fluid may be driven through at least part of the channel system at least partially caused by the centrifugal force, wherein optionally one or more further forces may be applied, such as capillary forces, pressure forces or forces caused by vacuum. The sample fluid may in at least one first part of the channel system be guided having at least one directional component towards the distal end. The sample fluid may subsequently in at least one second part of the channel system be guided having at least one directional component towards the proximal end, wherein the sample fluid may subsequently be guided into the chambers.
At least some of the chambers may be filled serially by the sample fluid. The sample fluid may enter the chambers through the inlet openings and leave the chambers through the outlet openings having a directional component towards the proximal end, before entering at least one subsequent chamber being located further towards the proximal end.
Preferably, the inlet opening and the outlet opening are located in close proximity. Thus, preferably, the inlet opening and the outlet opening of the chambers, preferably of all chambers, may be located such that, a connection between a center of the chamber and the inlet opening (such as the center of the inlet opening) and a connection between the center of the chamber and the outlet opening (e.g. the center of the outlet opening) enclose an angle of no more than 120°, preferably of no more than 90°, more preferably of no more than 60° and most preferably of no more than 50°. Preferably, after one chamber, e.g. one well, or more chambers are filled through the inlet opening, preferably completely, a flow of the sample fluid may be directed through the outlet opening to the venting channel without completely flowing through, e.g. without completely crossing, the filled chamber, due to the close proximity of the inlet opening and the outlet opening. Preferably, the sample fluid enters the chamber through the inlet opening having a first direction of flow and may leave the chamber through the outlet opening having a second direction of flow, wherein the first direction of flow and the second direction of flow preferably form a small angle of no more than 120°, preferably no more than 90°, more preferably of no more than 60° and most preferably of no more than 50°, Thereby, the above-mentioned effect of avoiding a flushing-out of the reagent from the chamber and a cross-contamination may be prevented.
Preferably, the reagent is located below the inlet opening and the outlet opening of the respective chamber containing the reagent. Thus, the reagent preferably is located further towards the distal end of the multi-chamber plate than the respective inlet opening and the respective outlet opening of the chamber.
Preferably, the at least one reagent is located at a distance from the inlet opening and the outlet opening of the chamber, preferably in all chambers. Thus, preferably, the reagent is located at a distance from the inlet opening and from the outlet opening which exceeds 10% of the diameter or equivalent diameter of the chamber (measured in the plane of the multi-chamber plate). More preferably, the distance exceeds 30% of the diameter or equivalent diameter, and most preferably exceeds 50% of the diameter or equivalent diameter.
Inlet/outlet channel junctions may be connected to both transversal sides of a main feeding/venting line, either alternating between both transversal sides, or just from one side or randomly distributed. The positions of the inlet/outlet channel junctions along the radial direction may be random or two inlet channel junctions may be arranged opposite to each other.
The main feeding line preferably may be filled in a counter-radial direction. Thus, at least one first part of the main feeding line being located further towards the distal end may be filled at an earlier point in time than at least one second part of the main feeding line being located further towards the proximal end. Preferably, the main feeding line is gradually filled in a direction having a directional component parallel to the counter-radial direction and most preferably being parallel to the counter-radial direction.
The present invention may provide controlled, complete filling of the chambers while strongly reducing the risk of cross-contamination of reagents, contained in the chambers, and trapping of gas bubbles in the chambers.
Summarizing the ideas of the present invention, the following items are preferred:
- Item 1: A multi-chamber plate, preferably for analytical purposes, the multi-chamber plate having a plurality of chambers and a channel system for filling the chambers with at least one sample fluid, the multi-chamber plate having a proximal end and a distal end, wherein a radial direction is defined from the proximal end to the distal end and wherein a centrifugal force is applicable parallel to the radial direction, wherein the channel system comprises at least one application site for applying the sample fluid to the channel system, the chambers each having at least one inlet opening and at least one outlet opening being separate from the inlet opening, wherein both the inlet opening and the outlet opening are positioned on a proximal side of the chambers, wherein the chambers are fillable through the inlet openings with the sample fluid driven by the centrifugal force, wherein the chambers are vented through the outlet openings, wherein at least one reagent is located in the chambers, the channel system having at least one main feeding line, the channel system having at least one main venting line, wherein the inlet openings are connected to the main feeding line at inlet channel junctions, wherein the outlet openings are connected to the main venting line at outlet channel junctions, wherein the inlet channel junctions are located further towards the distal end than the respective outlet channel junctions, wherein the inlet openings, the outlet openings, the inlet channel junctions and the outlet channel junctions are arranged such that, during the filling with the sample fluid, a venting of each chamber is possible until the respective chamber is completely filled with the sample fluid, wherein the main venting line and the main feeding line at least partially are separate from each other, wherein the main venting line and the main feeding line are fluidly connected, wherein the main venting line and the main feeding line are connected at the distal end of the multi-chamber plate at at least one connection point.
- Item 2: The multi-chamber plate according to one of the preceding items, wherein the main venting line and the main feeding line are partially identical.
- Item 3: The multi-chamber plate according to one of the preceding items, wherein the channel system is arranged such that chambers located further towards the distal end are filled before chambers located further towards the proximal end when the centrifugal force is applied.
- Item 4: The multi-chamber plate according to one of the preceding items, wherein the outlet openings have at least one tapered region.
- Item 5: The multi-chamber plate according to one of the preceding items, wherein the channel system is designed such that the sample fluid applied to the application site, driven by the centrifugal force, passes at least one first feeding line segment being directed in radial direction, before passing a second feeding line segment being directed in a counter-radial direction and entering the chambers from the second feeding line segment.
- Item 6: The multi-chamber plate according to one of the preceding items, wherein the reagent is separated from the sample fluid entering the chambers by at least one releasable barrier.
- Item 7: The multi-chamber plate according to one of the preceding items, wherein the channel system has at least one decant channel for overload protection of the channel system.
- Item 8: The multi-chamber plate according to one of the preceding items, wherein the channel system has at least one fluid restrictor device adapted for controlling a flow of the sample fluid through at least part of the channel system.
- Item 9: A filling system, comprising at least one multi-chamber plate according to one of the preceding items, the filling system further comprising at least one centrifuge, wherein the centrifuge is charged with the at least one multi-chamber plate, wherein the filling system is adapted to fill the at least one multi-chamber plate with at least one sample fluid.
- Item 10: The filling system according to the preceding item, wherein the centrifuge is arranged to put the multi-chamber plate in rotation around at least one rotation axis.
- Item 11: A method for filling a multi-chamber plate with at least one sample fluid, wherein a multi-chamber plate according to one of the preceding items referring to a multi-chamber plate is used, wherein a centrifugal force is applied at least essentially parallel to the radial direction, wherein the sample fluid is applied to at least one sample application site of the channel system, wherein the chambers are filled from at least one main feeding line and are vented into at least one main venting line, wherein the main venting line is separate from the main feeding line, wherein the chambers are filled at least with the sample fluid, the filling at least partially being driven by the centrifugal force, wherein the chambers are vented through the outlet openings in a direction having at least one directional component towards the proximal end, wherein, during the filling with the sample fluid, each chamber is vented until the respective chamber is completely filled with the sample fluid.
- Item 12: The method according to one of the preceding method items, wherein chambers being located further towards the distal end are filled before chambers being located further towards the proximal end.
- Item 13: The method according to one of the preceding method items, wherein the filling of the chambers through the inlet openings takes place having at least one directional component towards the distal end.
- Item 14: The method according to one of the preceding method items, wherein the sample fluid is driven through at least part of the channel system at least partially caused by the centrifugal force, wherein the sample fluid in at least one first feeding line segment of the channel system is guided having at least one directional component towards the distal end, wherein the sample fluid subsequently in at least one second feeding line segment of the channel system is guided having at least one directional component towards the proximal end, wherein the sample fluid subsequently is guided into the chambers.
- Item 15: The method according to one of the preceding method items, wherein at least some of the chambers are filled serially by the sample fluid, wherein the sample fluid enters the chambers through the inlet openings and leaves the chambers through the outlet openings having a directional component towards the proximal end, before entering at least one subsequent chamber being located further towards the proximal end.
- Item 16: The method according to one of the preceding method items, wherein the main feeding line is filled in a counter-radial direction.
Description of the drawingsFor a more complete understanding of the present invention, reference is established to the following description of preferred embodiments made in connection with accompanying drawings. The features disclosed therein may be realized in an isolated way or in combination with other features. The invention is not restricted to the embodiments. Identical reference numbers in the drawings refer to identical and/or functionally similar elements, which correspond to each other with regard to their functions.
In the figures:- Figure 1A shows a first embodiment of a multi-chamber plate according to the present invention with one main feeding line;
- Figure 1B
- shows another embodiment of a multi-chamber plate according to the present invention with two main feeding lines;
- Figure 2
- shows a partial view of a third embodiment of a multi-chamber plate according to the present invention, wherein the main feeding line acts also as the main venting line;
- Figure 3
- shows a partial view of a multi-chamber plate according to the present invention, wherein the outlet openings have at least one tapered region;
- Figure 4A
- shows a partial view of an embodiment of a multi-chamber plate according to the present invention, wherein the chambers may be filled serially;
- Figure 4B
- shows another partial view of an embodiment of a multi-chamber plate, wherein the chambers may be filled serially;
- Figure 5
- shows an embodiment of a multi-chamber plate according to the present invention comprising at least one intake reservoir, at least one waste reservoir and at least one decant channel;
- Figure 6
- shows an embodiment of a filling system according to the present invention; and
- Figures 7A-7E
- show a time sequence of an embodiment of a method for filling a multichamber plate according to the present invention.
Preferred embodimentsInFigure 1A, amulti-chamber plate 110 according to the present invention is shown. Themulti-chamber plate 110 may preferably be used for analytical purposes. Themulti-chamber plate 110 has a plurality ofchambers 112 and achannel system 114 for filling thechambers 112 with at least onesample fluid 113. Themulti-chamber plate 110 has aproximal end 116 and adistal end 118. A radial direction 120 is defined from theproximal end 116 to thedistal end 118. Acentrifugal force 122 is applicable parallel to the radial direction 120. The strength of thecentrifugal force 122 may be generated by placing themulti-chamber plate 110 into acentrifuge 180. The strength of thecentrifugal force 122 may be controlled by adjusting the rotation frequency of thecentrifuge 180. Furthermore, thechannel system 114 comprises at least oneapplication site 124 for applying thesample fluid 113 to thechannel system 114. Thechambers 112 each have at least oneinlet opening 126 and at least oneoutlet opening 128 being separate from theinlet opening 126. Both theinlet opening 126 and theoutlet opening 128 are positioned on aproximal side 130 of thechambers 112. Thechambers 112 are fillable through theinlet openings 126 with thesample fluid 113 by thecentrifugal force 122. Thechambers 112 are vented through theoutlet openings 128.
At least onereagent 200, which is symbolically shown in theFigures 7A to 7E, is located in thechambers 112. Thisreagent 200 may comprise a coating on at least part of at least one of a chamber wall of thechambers 112, an isolated amount ofreagent 200, a powder, a gel or any other physical shape and state or combinations thereof. Thechannel system 114 has at least onemain feeding line 132. Furthermore, thechannel system 114 has at least onemain venting line 134. In this embodiment, themulti-chamber plate 110 has onemain feeding line 132 and two main venting lines 134. Theinlet openings 126 are connected to themain feeding line 132 atinlet channel junctions 136. Theoutlet openings 128 are connected to the twomain venting lines 134 atoutlet channel junctions 138. Theinlet channel junctions 136 are located further towards thedistal end 118 than the respectiveoutlet channel junctions 138. This is indicated inFigure 1A by two dashedlines 140 representing the positions along the radial direction 120 of aninlet channel junction 136 and anoutlet channel junction 138, belonging to thesame chamber 112. Theinlet openings 126, theoutlet openings 128, theinlet channel junctions 136 and theoutlet channel junctions 138 are arranged such that, during the filling with thesample fluid 113, a venting of eachchamber 112 is possible until therespective chamber 112 is completely filled with thesample fluid 113.
In this embodiment, thechannel system 114 may have twomain venting lines 134 which are at least partially separated from themain feeding line 132. Themain venting lines 134 and themain feeding line 132 are fluidly connected.
Themain venting line 134 and themain feeding line 132 are connected at at least oneconnection point 135, which allows for a fluidic connection between themain venting line 134 and themain feeding line 132. This at least oneconnection point 135 is located close to thedistal end 118 of themulti-chamber plate 110. Thus, themain venting line 134 and themain feeding line 132 are connected at thedistal end 118 of themulti-chamber plate 110.
In this embodiment, thechannel system 114 is arranged such thatchambers 112 located further towards thedistal end 118 are filled beforechambers 112 located further towards theproximal end 116 when thecentrifugal force 122 is applied.
Ventingchannels 142 may be connected to theoutlet openings 128. The ventingchannels 142 are arranged such that gas, e.g. polluted fluid and/or air, being pushed out from thechambers 112 through the ventingchannels 142 has at least one velocity component anti-parallel to the radial direction 120. Feedingchannels 144 may be connected to theinlet openings 126. Feedingchannels 144 may be arranged such thatsample fluid 113 entering thechambers 112 through the feedingchannels 144 has at least one velocity component parallel to the radial direction 120.
In this embodiment, theoutlet openings 128 have at least onetapered region 146. The taperedregion 146 may be conically shaped, such as funnel-shaped, with the part having the reduced diameter being located on theproximal side 130.
Thechannel system 114 in this embodiment is designed such that thesample fluid 113 applied to theapplication site 124, driven by thecentrifugal force 122, passes at least one firstfeeding line segment 148 being directed in radial direction 120, before passing a secondfeeding line segment 150 being directed in acounter-radial direction 152 and entering thechambers 112 from the secondfeeding line segment 150.
One feature of this embodiment resides in the fact that thechannel system 114 is at least partially designed to have a V-shape 154, comprising a ventingchannel 142 and afeeding channel 144. Two of these V-shapes 154, separated by themain feeding line 132, form a W-shape 156.
Thereagent 200 may be separated from thesample fluid 113 entering thechambers 112 by at least one releasable barrier. Thereagent 200 preferably may be spotted and/or dried, e.g. thereagent 200 may comprise at least one dry chemical, e.g. as shown inFigures 7A-7E. The at least one releasable barrier may be selected from: a mechanically breakable barrier; a dissolvable barrier; a thermally breakable barrier; a chemically breakable barrier; a photo-chemically breakable barrier. Thechannel system 114 of this embodiment has oneintake reservoir 158 being connected to thesample application site 124 and being adapted to hold a supply 160 of thesample fluid 113 before feeding thesample fluid 113 into thechambers 112. Furthermore, thechannel system 114 may have at least one fluid restrictor device adapted for controlling a flow of thesample fluid 113 through at least part of thechannel system 114. The restrictor device may be preferably selected from: a narrowed passage; a valve, preferably ageometric valve 176; or a throttle.
The filling of themulti-chamber plate 110 disclosed in this embodiment with at least onesample fluid 113 preferably is forced by thecentrifugal force 122 applied at least essentially parallel to the radial direction 120, for example with an angle between thecentrifugal force 122 and the radial direction 120 smaller than +/- 20°, preferably smaller than +/- 10°, specifically smaller than +/- 5° and most preferably of 0°. Thesample fluid 113, preferably a liquid, is applied to theapplication site 124 of thechannel system 114. The on theproximal end 116 positionedintake reservoir 158 stores thesample fluid 113 and acts like a funnel by guiding thesample fluid 113 in the radial direction 120 into thechannel system 114. In this embodiment, themulti-chamber plate 110 may be filled from thedistal end 118 to theproximal end 116, and, thus,chambers 112 being located further towards thedistal end 118 are filled beforechambers 112 being located further towards theproximal end 116. Thesample fluid 113 is driven through at least part of thechannel system 114 at least partially caused by thecentrifugal force 122, wherein thesample fluid 113 in at least one firstfeeding line segment 148 of thechannel system 114 is guided-having at least one directional component towards thedistal end 118. Thesample fluid 113 subsequently in at least one secondfeeding line segment 150 of thechannel system 114 may be guided having at least one directional component towards theproximal end 116. Thesample fluid 113 may subsequently be guided into thechambers 112.
The filling of thechambers 112 through theinlet openings 126 may take place having at least one directional component towards thedistal end 118. While thechambers 112 are filled, air, other gases and/orpolluted sample fluid 113 may be pushed out towards thedistal end 118 of themulti-chamber plate 110. This process is also forced by thecentrifugal force 122, as the density of air, especially air bubbles, or other gases is commonly lower than the density of thesample fluid 113, especially if thesample fluid 113 is a sample liquid. Thus, the filling, and the venting, may at least partially be driven by thecentrifugal force 122, wherein thechambers 112 may be vented through theoutlet openings 128 in a direction having at least one directional component towards theproximal end 116.
The filling speed may be controlled via the flow resistance in different parts of themulti-chamber plate 110. In particular, the firstfeeding line segment 148, which preferably connects theintake reservoir 158 with themain feeding line 132, is suited to disclose a fluid restrictor device, for example a flow resistance to control the filling speed in combination with the centrifuge speed. A slower filling may cause a better, preferably a more equally, distribution of thesample fluid 113 in a direction perpendicular to the radial direction 120.
In this embodiment, during the filling of thechambers 112, gas trapping or trapping of air bubbles in thechambers 112 may be avoided because the ventingchannels 142 are connected towards theproximal end 116 of thechambers 112. Due to thecentrifugal force 122, thesample fluid 113 will be forced towards thedistal end 118, while air or air bubbles or other gases, whose density may be lower than the density of thesample fluid 113, may be pushed towards theproximal end 116, where the ventingchannel 142 guides the air or the air bubbles to themain venting line 134.
As theapplication site 124 in this embodiment is located at thedistal end 118, flushing inside thechambers 112 is limited during the filling process, as the possibility of convection ofpresent reagents 200, for example chemicals, inside thechambers 112 and out of thechambers 112 is limited. Preferably, thereagent 200, such as a highly-concentrated chemical fraction, may have a higher density than thesample fluid 113, such that thereagent 200 is forced preferably towards thedistal end 118 and thus may be forced to remain in thechambers 112. Preferably, thereagent 200, e.g comprising at least one dry chemical, may be dissolved by thesample fluid 113. The mass density of the dissolved, preferably high-concentrated,reagent 200, e.g. accumulated to a concentrated mixture, preferably may be higher than thesample fluid 113 withoutreagent 200. The concentrated mixture may be centrifugated towards the radial direction 120, preferably in direction to thedistal end 118, preferably into thechambers 112. This mechanism preferably may support avoiding washing out ofreagents 200 from thechambers 112. Furthermore, anyreagent 200 that happens to be flushed out of achamber 112 preferably may flow into amain venting line 134, but cannot flow into themain feeding line 132 due to the arrangement of the ventingchannel 142 and the feedingchannel 144 to themain venting line 134 and themain feeding line 132, as described above. Thus, a reliable one-way flow in the ventingchannel 142, themain venting lines 134 and in thefeeding channel 144, themain feeding line 132 is realized, supported by the positioning of theinlet channel junctions 136 and theoutlet channel junctions 138, which are shifted to each other in respect to the radial direction 120 as described above. Thus, not only contamination is avoided, but since feeding and venting takes place via separate channels, optimal filling is obtained.
InFigure 1B, a second embodiment according to the present invention is depicted, which is a modification of the first embodiment, as presented inFigure 1A. Instead of onemain feeding line 132 and twomain venting lines 134, the setup shown inFigure 1B comprises twomain feeding lines 132 and two main venting lines 134. Other embodiments with a higher or lower number ofmain feeding lines 132 and/or a higher or lower number ofmain venting lines 134 may be possible. Furthermore,Figure 1B shows thelevel 164 of thesample fluid 113 at a random intermediate point in time during filling. Thelevel 164 of thesample fluid 113 may be located perpendicular to the radial direction 120 in between the first row ofinlet channel junctions 136 and the first row ofoutlet channel junctions 138. This demonstrates that the point of time for filling may be a function monotonically decreasing with the radial coordinate of thechamber 112, which may be one of the advantages ofmulti-chamber plates 110 according to the present invention. As theinlet channel junctions 136 are located further towards thedistal end 118 than the respectiveoutlet channel junctions 138, gas trapping inside thechambers 112 may be avoided during the filling process. Themain feeding lines 132 and themain venting lines 134 are arranged in parallel in this embodiment. Themain venting lines 134 and themain feeding lines 132 may also be arranged with a non-vanishing angle between themain feeding lines 132 and/or themain venting lines 134, which may be for example an angle smaller +/- 20°, preferably smaller +/- 10°, specifically smaller +/- 5° and most preferably an angle of 0°.
Figure 2 shows a part of another embodiment according to the present invention.Figure 2 focuses on possible modifications of the geometries of the ventingchannels 142 and the feeding-channels 144 of amulti-chamber plate 110, which may be designed similar to the embodiment shown inFigure 1A. A drawback of achannel system 114 with two channels, oneventing channel 142 and onefeeding channel 144 perchamber 112 may be the stability of thesample fluid 113 in thechambers 112. A pressure difference, occurring between a ventingchannel 142 and afeeding channel 144, may cause instabilities. Achannel system 114 designed with two channels perchamber 112 may be less robust in combination with a sealing method, for example based on filling at least a part of thechannel system 114 for example with a material containing a polymer. Thus, a compromise between contamination-free filling and fluidic stability of thesample fluid 113 in thechannel system 114 may be obtained by modifying the design of thechannel system 114 described in the first embodiment inFigure 1A containing V-shapes 154 into a design in which both channels of the V-shapes 154 are connected to one main line 166. This main line 166 may be a combination of themain feeding line 132 and themain venting line 134 to one element. Preferably, themain venting line 134 and themain feeding line 132 may be at least partially identical. The feedingchannel 144 and the ventingchannel 142 of onechamber 112 may be oriented parallel or under an inclination angle, preferably an angle smaller 90°, to increase the distance between theinlet channel junction 136 and theoutlet channel junction 138. Thus, thechannel system 114 of this embodiment may contain U-shapes 155 and/or V-shapes 154.
Furthermore, complete air-free filling may still be guaranteed, similar as in the embodiments described above, and additionally the main line 166 may be filled with a material, like a polymer, for sealing. The use of other fluid restrictor devices, such as a different kind of a valve, preferably ageometric valve 176, and/or a throttle, may be possible. The performance of the filling and sealing may be optimized by choosing optimized fluid restrictor devices and resistances. A larger distance between theinlet channel junction 136 and theoutlet channel junction 138 may result in a safer filling, preferably a bubble-free filling of thechambers 112 and a suppression of the transport ofreagents 200, in a dry or dissolved state, out of thechambers 112 and contamination betweendifferent chambers 112.Figure 2 shows an embodiment of the present invention comprising three main lines 166 for feeding thechambers 112 from thedistal end 118 to theproximal end 116. This is one possible design, other designs with a higher or lower number of main lines 166 are possible, such as designs providing a filling via one main line 166. Thus,multi-chamber plates 110 having only the one main line 166 in the center of themulti-chamber plate 110 are possible, though filling and venting might be less optimal than by using more than one main line 166.
Theinlet openings 126 may be located at the mostproximal side 130 of thechambers 112 and theinlet channel junctions 136 might be connected at different positions of the main line 166. The feeding of the main line 166 may be performed from thedistal end 118.
Figure 3 shows a part of another embodiment of amulti-chamber plate 110 according to the present invention. The design of the totalmulti-chamber plate 110 may be designed according to the present invention, thus may be similar to the presentedmulti-chamber plate 110 inFigure 1A. InFigure 3, optimized geometries of achannel system 114 are shown to enhance air-free filling. The characteristics explained in the following may also be applied to other possible embodiments of the present invention, either in a combination described in the following or in different combinations.
Sharp corners and edges and steps between channels, like the ventingchannels 142, the feedingchannels 144, different lines, like themain feeding lines 132, themain venting lines 134 or the main lines 166 andchambers 112 may facilitate air-bubble trapping. To avoid these effects,outlet openings 128 may have at least onetapered region 146. The geometry of thechannel system 114 may comprise conically shapedoutlet openings 128 of thechambers 112 and rounded edges and corners, sketched inFigure 3 andFigure 2. This emphasizes that these characteristic geometries may be applicable not only tochambers 112 in which the ventingchannel 142 and the feedingchannel 144 are comprised in one main channel 168, but also in different chamber designs, for example in the embodiments described inFigure 1A,Figure 1B,Figure 2,Figure 4A,Figure 4B or Figure 5.Tapered regions 146, like conically shaped regions, rounded edges and rounded corners, minimize the chance on trapping gas, minimizing gas-bubbles. Thetapered regions 146, preferably the conically shapedoutlet openings 128, may act as a funnel that guides the vented air towards the ventingchannel 142. Thus, in embodiments withseparate venting channel 142 and feedingchannel 144,sample fluid 113 and flowing gas may be clearly separated and may not interfere.
InFigure 4A andFigure 4B, possible modifications of at least a part of achannel system 114 of amulti-chamber plate 110 are depicted. The aspects shown in these two figures may even be implemented into sections of thechannel system 114 according to other embodiments of the present invention.
InFigure 4A andFigure 4B, embodiments for serially filling thechambers 112 with thesample fluid 113 are shown. At least some of thechambers 112 may be filled serially by thesample fluid 113 inmulti-chamber plates 110 according to the present invention, wherein thesample fluid 113 enters thechambers 112 throughinlet openings 126 and leaves thechambers 112 throughoutlet openings 128 having a directional component towards theproximal end 116, before entering at least onesubsequent chamber 112 being located further towards theproximal end 116. By connecting thechambers 112 in a serial way, gas may be pushed out in one direction, preferably essentially incounter-radial direction 152, while thechambers 112 are filled from thedistal end 118 of thechambers 112. This serial filling method may be used not only in combination withcentrifugal forces 122, but also with other filling methods like filling by pressure, vacuum or capillary forces. Generally, serial filling methods are known from prior art which are not applicable for the use withreagents 200 located in thechambers 112, as cross-contamination may occur. Thus, thereagent 200 may be separated from thesample fluid 113 entering thechamber 112 by at least one releasable barrier. Controlled passivation of thereagents 200 in thechambers 112 during filling may suppress contamination. The release of thereagents 200 may only happen after allchambers 112 are filled with thesample fluid 113 and the fluid flow is stopped. Preferably, the method of separating thereagent 200 from thesample fluid 113 may be selected from one or more of the following:
- 1.) Covering thereagent 200 with a coating that:
- dissolves slowly after contacting thesample fluid 113. For example, a dissolvable polymer or other coating materials that do not interfere with thereagent 200 may be used.
- dissolves after being triggered for example by applying a certain temperature or by illumination of the coating.
- ruptures in a controlled, triggered way, for example by temperature, illumination, mechanical forces or other physical or chemical methods.
- 2.) Storing thereagents 200 in a container which can be dissolved or opened like described above.
- 3.) Containingreagents 200 in thechannel system 114 which releases thereagents 200 in a controlled and/or triggered way.
- 4.) Separating thereagents 200 from thesample fluid 113 via a membrane that can be opened or ruptured.
A possible basic design for serial filling is shown inFigure 4A. During filling, thesample fluid 113 flows completely through thechambers 112, also through already completely filledchambers 112. In order to avoid contamination, methods for dissolving of thereagents 200 during filling as described above may be used.
Figure 4B shows a part of another embodiment of amulti-chamber plate 110, where improvements of the geometry of thechannel system 114 may be used for slowly-dissolvingreagents 200 or applications that are tolerant to slight contaminations. A siphon kind ofchannel 170 may centrifuge heavier fractions of thesample fluid 113 into thechambers 112 and may limit flow-through of filledchambers 112 to a minimum. In filledchambers 112, the flow path may be shortened.Sample fluid 113 may no longer penetrate the filledchambers 112, or at least penetrate much less into the filledchambers 112. Thus, transport ofreagents 200 from the filledchambers 112 into thesubsequent chambers 112 may be reduced. The intensity of the remaining convection and contamination depends on the speed of the flow of thesample fluid 113. The speed of the flow of thesample fluid 113 and thus thereagent 200 transport may be further reduced by increasing the flow resistance of themain feeding lines 132 by at least one fluid restrictor device adapted for controlling the flow of thesample fluid 113 through at least part of thechannel system 114. Besides the methods described above, this can be realized for example by narrowing or increasing the length of a channel, preferably of themain feeding line 132.
The embodiments shown inFigure 4A andFigure 4B are examples for a serial filling design. In these embodiments, the ventingchannel 142 of onechamber 112 is the feedingchannel 144 of thechamber 112, next to be filled. Theinlet openings 126 preferably may be located at theproximal side 130 of thechambers 112 and theoutlet openings 128 are located on the distal side of thechambers 112. The firstfeeding line segment 148 may connect only to the mostdistal chamber 112.Inlet channel junctions 136 andoutlet channel junctions 138 may be close to each other.
InFigure 5, another embodiment for amulti-chamber plate 110 according to the present invention, preferably for analytical purposes, is shown. Thismulti-chamber plate 110 has a plurality ofchambers 112 and achannel system 114 for filling thechambers 112 with at least onesample fluid 113. Themulti-chamber plate 110 has aproximal end 116 and adistal end 118, wherein a radial direction 120 is defined from theproximal end 116 to thedistal end 118 and wherein acentrifugal force 122 is applicable parallel to the radial direction 120. Thechannel system 114 comprises at least oneapplication site 124 for applying thesample fluid 113 to thechannel system 114. Thechambers 112 each have at least oneinlet opening 126 and at least oneoutlet opening 128 being separate from theinlet opening 126. Both theinlet opening 126 and theoutlet opening 128 are positioned on aproximal side 130 of thechambers 112. Thechambers 112 are fillable through theinlet openings 126 with thesample fluid 113 driven by thecentrifugal force 122. Thechambers 112 are vented through theoutlet openings 128. At least onereagent 200, which is not shown explicitly inFigure 5, is located in thechambers 112. Methods for controlled passivation of thereagents 200 as described above may be used. Thechannel system 114 has at least onemain feeding line 132, in this embodiment preferably onemain feeding line 132, and at least onemain venting line 134, in this embodiment preferably only onemain venting line 134. Themain feeding line 132 and themain venting line 134 of this embodiment are directed at least essentially perpendicular to the radial direction 120. Essentially perpendicular means, the angle between the radial direction 120 and themain feeding line 132 or themain venting line 134 may be 30° to 150°, preferably 60° to 120°, specifically 70° to 110° and most preferably 90°. Theinlet openings 126 are connected to themain feeding line 132 atinlet channel junctions 136, wherein theoutlet openings 128 are connected to themain venting line 134 atoutlet channel junctions 138. Theinlet channel junctions 136 are located further towards thedistal end 118 than the respectiveoutlet channel junctions 138.
Thechannel system 114 shown inFigure 5 has amain venting line 134 which at least partially is separate from themain feeling line 132, wherein themain venting line 134 and themain feeding line 132 are fluidly connected.
Thechannel system 114 is arranged such thatchambers 112 located further towards thedistal end 118 are filled beforechambers 112 located further towards theproximal end 116 when thecentrifugal force 122 is applied. Ventingchannels 142 may be connected to theoutlet openings 128. The ventingchannels 142 furthermore may be arranged such that gas being pushed out from thechambers 112 through the ventingchannels 142 has at least one velocity component anti-parallel to the radial direction 120. Preferably, the velocity of the gas may be at least in a region around theproximal end 116 of the ventingchannel 142 essentially anti-parallel to the radial direction 120.
Ventingchannels 142 may be connected to theoutlet openings 128. Furthermore, theoutlet openings 128 may have at least onetapered region 146. Thechannel system 114 may be designed such that thesample fluid 113 applied to theapplication site 124, driven by thecentrifugal force 122, passes at least one firstfeeding line segment 148 being directed in radial direction 120, not necessarily parallel to the radial direction 120, but having a directional component parallel to the radial direction 120. After that, a secondfeeding line segment 150 is passed being directed incounter-radial direction 152. Thechambers 112 may be entered from the secondfeeding line segment 150.
Thereagent 200 may be separated from thesample fluid 113 entering thechambers 112 by at least one releasable barrier. The at least one releasable barrier may be selected from: a mechanically breakable barrier; a dissolvable barrier; a thermally breakable barrier; a chemically breakable barrier; or a photo-chemically breakable barrier. Thechannel system 114 may at least have oneintake reservoir 158 being connected to thesample application site 124 and being adapted to hold a supply 160 of thesample fluid 113 before feeding thesample fluid 113 into thechambers 112. Themulti-chamber plate 110 described in this embodiment has at least onewaste reservoir 172 which is adapted to holdexcess sample fluid 113 after filling of thechambers 112. Furthermore, thischannel system 114 has at least onedecant channel 174 for overload protection of thechannel system 114. Thedecant channel 174 may ensure complete filling of thechambers 112, e.g. the wells. Thedecant channel 174 preferably may have at least one bypass channel bypassing amain feeding line 132 and/or amain venting line 134. According to a siphon principle, a part of thechannel system 114 preferably may be positioned further to thedistal end 118 than theintake reservoir 158. Due to the leveling effect during centrifugation, allchambers 112 can be completely air-free filled without losingsample fluid 113. In this embodiment or other embodiments, the possibility to determine thefluid level 164 may be provided, such as by communicating feedingchannels 144 of different columns and/or a siphon effect and/or by themain venting line 134. Themain venting line 134 may be arranged at the most proximal position. The distance betweenoutlet openings 128 andinlet openings 126 may be preferably minimal. Thechannel system 114 may have at least one fluid restrictor device adapted for controlling a flow of thesample fluid 113 through at least part of thechannel system 114. Thus, via tuning of the channel resistances and eventually includinggeometric valves 176, using surface tension effects, the filling and contamination performance may be optimized.
An excess ofsample fluid 113 may be decanted through thedecant channel 174 after allchambers 112 have been filled. Thedecant channel 174 may assure complete filling and overload protection.Figure 1B to 4B only show parts of different embodiments ofmulti-chamber plates 110. For other components of the showed embodiments, reference may be made to the above-mentioned embodiments, such as the embodiments shown inFigures 1A and5.
Figure 6 shows an embodiment of afilling system 178 according to the present invention, comprising at least onemulti-chamber plate 110 as described above. The fillingsystem 178 further comprises at least onecentrifuge 180. Thecentrifuge 180 is a device adapted to generate acentrifugal force 122, to exposure acentrifugal force 122 on themulti-chamber plate 110 and on thesample fluid 113.
Thecentrifuge 180 is charged with the at least onemulti-chamber plate 110. Preferably thecentrifuge 180 may be charged with twomulti-chamber plates 110, as shown inFigure 6. The fillingsystem 178 is adapted to fill the at least onemulti-chamber plate 110, preferably bothmulti-chamber plates 110, with at least onesample fluid 113 as described above, driven by thecentrifugal force 122 generated by thecentrifuge 180.
Thecentrifuge 180 may be arranged to put themulti-chamber plate 110, preferably bothmulti-chamber plates 110, in rotation, preferably around at least one, preferably one,rotation axis 182. Therotation axis 182 may be an axis around which at least a part of themulti-chamber plate 110 may rotate, e.g. during filling. Preferably, therotation axis 182 may be a fixed axes. Preferably, therotation axis 182 may be located separately from themulti-chamber plate 110, e.g. in such way that the wholemulti-chamber plate 110 may rotate around therotation axis 182.
Thecentrifuge 180 may contain one or more receptacles for receiving themulti-chamber plate 110 and, preferably, for reversibly fixing themulti-chamber plate 110. Preferably, themulti-chamber plate 110 may be fixed at thecentrifuge 180 by at least onebracket 184. Generally, as outlined above, the at least onesample fluid 113 may be applied to themulti-chamber plate 110 before, during or after receiving themulti-chamber plate 110 in the at least one receptacle, such as in the at least onebracket 184. In the present embodiment and in other embodiments of the present invention, the receptacle may be adapted such that theapplication site 124 of themulti-chamber plate 110 is still accessible for sample application after insertion of themulti-chamber plate 110 into the receptacle, before starting of the centrifugation process. However, other embodiments are possible.
Preferably, themulti-chamber plate 110 may be fixed at theproximal end 116 of themulti-chamber plate 110. Preferably, thedistal end 118 may be located further away from therotation axis 182 than theproximal end 116, e.g. to generate acentrifugal force 122 acting at least essentially parallel to the radial direction 120, e.g. with a deviation from parallel arrangement by less than 10°, less than 5° or even less than 2°. Preferably thecentrifugal force 122 may point to thedistal end 118 of themulti-chamber plate 110. Thecentrifugal force 122 may be added with thegravitational force 186 to an effective force 188 pointing to a direction between thecentrifugal force 122 and the direction of thegravitational force 186, preferably parallel to the radial direction 120. Thecentrifugal force 122 and/or thegravitational force 186 and/or the effective force 188 may act on themulti-chamber plate 110, preferably on thesample fluid 113. Preferably, thesample fluid 113 may be pushed and/or filled into themulti-chamber plate 110, preferably thechambers 112, by at least one of these forces, preferably mainly by thecentrifugal force 122.
The fillingsystem 178, preferably thecentrifuge 180, may comprise at least one control system 190. The control system 190 may be a device which may be adapted to control and/or to drive the fillingsystem 178 and/or thecentrifuge 180. The control system 190 may comprise at least one computer 192 and/or at least one electrical connector and/or at least one electrical line and/or at least one interface and/or at least one display and/or at least one user interface, e.g. at least oneswitch 194, e.g. for switching on or switching off thefilling system 178 and/or thecentrifuge 180. The control system 190 further may comprise at least onetuner 196 for changing the rotation velocity and/or the direction of the rotation and/or the strength of thecentrifugal force 122 induced by thecentrifuge 180. Thecentrifuge 180 further may comprise at least oneactuator 198, e.g. at least one engine, preferably an electrical engine, and/or at least one hand driven actuator. Theactuator 198 may be a device to bring at least a part of thecentrifuge 180 into rotation. Theactuator 198 may be connected with the control system 190.
Further, the fillingsystem 178 may optionally comprise at least one device for cooling and/or heating thesample fluid 113 and/or to control the temperature of thesample fluid 113, e.g. at least one heater and/or at least one cooler and/or at least one thermometer. Theflling system 178 also may comprise at least one optical detection system, such as a setup comprising at least one high-speed camera and/or at least one other sensor, such as at least one photodiode and/or at least one phototransistor and/or at least one capacitive sensor and/or at least one inductive sensor, and/or at least one camera synchronized with thecentrifuge 180 for recording at least one image or at least one sequence of images indicating the filling and/or venting status of thechambers 112 during the filling process, which may allow for an evaluation of a filling and/or venting schedule. This detection system is not depicted inFigure 6 and may be arranged above and/or below one or both of thebrackets 184, with a direction of view e.g. parallel and/or transverse to therotation axis 182. The filling status and/or the venting status may be controlled and/or used, preferably by the control system 190 and/or thefilling system 178. The optical detection system and the control system 190 may be connected, e.g. by at least one interface. The optical setup also may be used for detecting optical properties of thesample fluid 113, e.g. the color, e.g. for analysis, e.g. after and/or before at least one reaction between thesample fluid 113 and thereagent 200.
Figure 7A to 7E show a method according to the present invention for filling amulti-chamber plate 110 with at least onesample fluid 113, particularlyFigures 7A to 7E show the filling of themulti-chamber plate 110 for different points in time, progressing fromFigure 7A to 7E. Figures 7A to 7E may show an image sequence, e.g. taken by the optical setup of thefilling system 178 described above.
Themulti-chamber plate 110 preferably may be amulti-chamber plate 110 according to the present invention as described above, particularly amulti-chamber plate 110 as shown inFigure 1A and described above. In theFigures 7A to 7E only a part of themulti-chamber plate 110 is shown. Themulti-chamber plate 110 has a plurality ofchambers 112 and achannel system 114 for filling thechambers 112 with thesample fluid 113. Thechambers 112 each have at least oneinlet opening 126 and at least oneoutlet opening 128 being separate from theinlet opening 126. Themulti-chamber plate 110 has aproximal end 116, not shown in theFigures 7A to 7E; but e.g. inFigure 1A, and adistal end 118. A radial direction 120 is defined from theproximal end 116 to thedistal end 118. Acentrifugal force 122 is applied at least essentially parallel to the radial direction 120. Both theinlet opening 126 and theoutlet opening 128 are positioned on aproximal side 130, wherein thesample fluid 113 is applied to at least onesample application site 124 of thechannel system 114, which is not shown in theFigures 7A to 7E but e.g. inFigure 1A. At least onereagent 200 may be located in thechambers 112. As outlined above, in this embodiment or in other embodiments of the present invention, allchambers 112 may be loaded with thesame reagent 200. Alternatively, thereagent 200 might be varied, such that at least afirst chamber 112 exists, having at least onefirst reagent 200 therein, and at least onesecond chamber 112 exists having at least onesecond reagent 200 therein, wherein thefirst reagent 200 and thesecond reagent 200 may be different with regard to at least one property, such as the type of thereagent 200. Thereagents 200 may be liquid, preferably thereagents 200 may be dried.
Thechambers 112 are filled from at least onemain feeding line 132 and are vented into at least onemain venting line 134. Themain venting line 134 is separate from themain feeding line 132. Theinlet openings 126 are connected to themain feeding line 132 atinlet channel junctions 136. Theoutlet openings 128 are connected to themain venting line 134 atoutlet channel junctions 138. Theinlet channel junctions 136 are located further towards thedistal end 118 than the respectiveoutlet channel junctions 138. Thechambers 112 are filled at least with thesample fluid 113. The filling at least partially is driven by thecentrifugal force 122. Thechambers 112 are vented through theoutlet openings 128 in a direction having at least one directional component towards theproximal end 116. During the filling with thesample fluid 113, eachchamber 112 is vented until therespective chamber 112 is completely filled with thesample fluid 113.
Themulti-chamber plate 110 used in the method for filling amulti-chamber plate 110 may be amulti-chamber plate 110 according to the present invention as described above. In the method for filling amulti-chamber plate 110 thefilling system 178 according to the present invention as described above and shown inFigure 6 may be used.
Thechambers 112 being located further towards thedistal end 118 may be filled beforechambers 112 being located further towards theproximal end 116.
The filling of thechambers 112 through theinlet openings 126 may take place having at least one directional component towards thedistal end 118.
Thesample fluid 113 may be driven through at least part of thechannel system 114 at least partially caused by thecentrifugal force 122. Thesample fluid 113 in at least one firstfeeding line segment 148 of thechannel system 114, as e.g. shown inFigure 7A, may be guided having at least one directional component towards thedistal end 118, wherein thesample fluid 113 subsequently in at least one secondfeeding line segment 150 of thechannel system 114 may be guided having at least one directional component towards theproximal end 116, as e.g. shown inFigure 7B, wherein thesample fluid 113 subsequently may be guided into thechambers 112, as shown inFigures 7C to 7E.Small arrows 202 in theFigures 7A to 7E indicate the direction of a flow of thesample fluid 113.
At least some of thechambers 112 may be filled serially by thesample fluid 113. Thesample fluid 113 may enter thechambers 112 through theinlet openings 126 and may leave thechambers 112 through theoutlet openings 128 having a directional component towards theproximal end 116, e.g. before entering at least onesubsequent chamber 112 being located further towards theproximal end 116.
Themain feeding line 132 may be filled in acounter-radial direction 152.
Described layouts, e.g. as shown in the figures, may provide controlled, complete filling of thechambers 112 while strongly reducing the risk of cross-contamination ofreagents 200, contained in thechambers 112, and trapping of gas bubbles in thechambers 112.