The filtering technique and filter of haemocyte in a kind of removal blood sampleTechnical field
When being handled the present invention relates to Laboratory blood sample and other biological samples, especially in Clinical Test LabA kind of filtering technique and filter design for haemocyte in quick separating blood sample.
Background technique
In Clinical Test Lab, blood sample is one of most common sample survey.The acquisition of blood sample is usualIt is realized using vacuum blood collection tube or needle tubing.New blood is unstable after leaving human body, and agglutinating reaction can occur for haemocyte.Therefore it generally requires and the reagents such as anti-coagulants inhibition blood pool is previously added and encapsulated in heparin tube, then pass through centrifugation point againFrom removing haemocyte.In many Clinical laboratory tests, including biochemical diagnosis, immunodiagnosis, molecular diagnosis, gene sequencing etc.In project, the presence of haemocyte and the cracking of haemocyte can bring interference to clinical test results in blood sample, increase and examineAs a result uncertainty.This influence to inspection result will lead to the false negative rate and false positive rate for increasing inspection result.
In order to reduce the interference of haemocyte bring, in the operation of clinical examination, the method for generalling use centrifuge separation is goneExcept the haemocyte in blood.In many clinical labororatories, it is a step open type manual operations that centrifugation, which carrys out washed corpuscles,.GenerallyIn the case of, if first collecting dry-eye disease, concentrate centrifugally operated together.The length of time of sample storage and the difference of condition of storage are rightThe cracking degree of haemocyte also has different influences.Simultaneously as the model of centrifuge, operating condition and the habit of operatorIt is used to be difficult to standardize, so that the processing of blood sample is difficult to standardize, to bring uncertainty to clinical test results.ThisKind operation also will increase the possibility of human operational error.
Existing centrifugally operated needs additional centrifugation apparatus and processing time, examines in many real-time tests and emergencyUnder scene, especially disaster field, in field, in battlefield and ambulance, sample survey do not have conditional pass centrifuge comeIt handles blood sample and removes haemocyte.And much examine project that cannot use the whole blood with haemocyte due to the limitation of inspection technologySample is as test samples.In this case, it is accordingly required in particular to blood in a kind of quick and complete removal blood of standardized energy simplicityThe method of cell.
Summary of the invention
In view of the deficiencies of the prior art, the present invention provides a kind of new filtering technique and a variety of filter designs,The haemocyte in blood sample can be quickly and easily removed, plasma sample is directly obtained.
The present invention program passes through by-pass filtration or multistage filtering technology using porous filter medium, in blood samplingHaemocyte in filtering retention blood sample saves the sample treatment operating time without using centrifugally operated.This filterFeature are as follows: its level-one or primary filter use the three-dimensional porous filter medium of fiber accumulations.This netted structure of three-dimensional fiber is (againReferred to as spongelike structure) it can be one or more forms such as filter paper, planar film, tubulose.The particle entrapment of this porous mediaEffect can be characterized with particle entrapment aperture.Commonly use that retention ratio reaches certain standard in the retention aperture of filter mediumThe diameter of grain.Common retention ratio is 90~95%.The retention aperture of the porous media used in the present invention for 10 microns orIt is smaller.When blood sample passes through by-pass filtration, haemocyte can not only be retained by the surface of filter medium, can also be moreFiber filament in the medium of hole stops or absorption.This porous media has mature application in immunochromatography technique.But exempting fromIn epidemic disease chromatographic technique, blood plasma cannot be separated and collected also not from porous media.
By-pass filtration can remove the haemocyte of the overwhelming majority, but cannot be guaranteed point of complete haemocyte and blood plasmaFrom.Haemocyte is completely removed if necessary, can be filtered with the retention smaller secondary filter medium in aperture after by-pass filtration.For example remaining haemocyte is retained as the second level or secondary filter by hollow-fibre membrane or plane fibers film.The second levelThe membrane aperture of filtering is generally less than the diameter of haemocyte, and retention aperture can be between 0.2 micron~3 microns of range.HereHollow-fibre membrane or plane fibers film can be secondary filtration structure, while being also possible to the support knot of by-pass filtration mediumStructure.The planar film of folding can also provide the collection channel of the blood plasma through film.If not requiring 100% cell retention, secondThe hollow-fibre membrane or plane fibers film of grade can collect the blood of filtering with porous collecting pipe.One end of this collecting pipeClosing, the other end access the plasma outlet port of filter.There are aperture or fluting in collecting pipe side, by the blood of porous media filterSlurry can be entered inside collecting pipe by these apertures or fluting and be pooled to filter outlet.If using double-filtrationThe function of mechanism, this double-filtration can be realized by Integral filter design, can also pass through concatenated multistage filteringDevice is distributed to realize.In concatenated filter, primary porous media can be as coarse filtration, and secondary filter medium can be asRefined filtration.
By the present invention in that this porous media is cut into phase with the flake porous medium in aperture and thickness optimizationSame or different shape will fit together in filter core according still further to specific mode with the porous media of these geometriesTo increase the contact area of sample and filter medium.The import of blood sample is reserved in the design of filter and filter core and is dividedThe collection of cloth channel and blood plasma and exit passageway.
In the present invention program, filter can be designed as a kind of design scheme of individual packages, and the filtrate of filter goes outMouth end is connected with vacuum blood collection tube or syringe, and the arrival end of filter is connected with the conduit of blood collection needles, is adopted using vacuumThe negative pressure of vacuum of blood vessel twitches the negative pressure of syringe formation as filtration driving force.The schematic diagram of design scheme such as Fig. 1 andFig. 2.When acquiring new blood from human body, blood stream is trapped through filter, haemocyte, and blood plasma is then flowed by filterIn heparin tube or syringe.Using this filtering scheme, blood sampling is separated with haemocyte and can be completed with a step.
Filter can have independent vacuum, by installing pipe clamp or valve in inlet and outlet.After vacuumizing, closeInlet and outlet keeps vacuum；Can also blood drawing when and vacuum blood collection tube share vacuum.Filter may be designed in advanceWith vacuum blood collection it is pipe integrated to facilitate operation.Blood filter can be fixed on vacuum blood collection tube with clip or other meansTop, as shown in Figure 3.After blood sampling and filtering, clip is opened, filter is abandoned, eliminates the blood plasma sample of haemocyteThis collection is in heparin tube.This filter can also be encapsulated in the inside of vacuum blood collection tube, after filtering, take outFilter obtains the heparin tube that blood plasma is housed.
Can make to take a blood sample and remove haemocyte single stepping using the present invention program and complete, it is easy quickly, abandon completely fromHeart operation, is not limited by equipment and place, substantially shortens the time needed for obtaining blood plasma, while can also be by blood sampling and separationPlasma procedure standardization.
Detailed description of the invention
Fig. 1: filter and vacuum blood collection tube are combined
Fig. 2: filter and syringe are combined
Fig. 3: filter and vacuum blood collection tube integral structure
Fig. 4: gear-like filter core design diagram
Fig. 5: the dish-like filter core design diagram of size
Fig. 6: radial hollow candle filter
Fig. 7: it is vertically arranged filter core design diagram
The specific embodiment of scheme of the invention
Filter of the invention is described in further detail combined with specific embodiments below.Following embodiments be in order intoOne step illustrates some currently preferred embodiments of the present invention, and not all embodiments.Those skilled in the art are creative in no progressMade under the premise of labour based on the other embodiment of the present invention, belong to the scope of the present invention.
Embodiment 1
As the specific design scheme of one kind of the invention, the filter membrane of first order filtering uses cellular glass fiber filament filter medium,The product (LF-D23) or (CF-D23) that specifically can be IWTremont are also possible to GE Healthcare's (GE medical treatment)The similar products such as Whatman Fusion5, CF/DVA, LF1, MF&VF2.It is also returned simultaneously as plasma sample as secondary filtrationThat receives channel can be hollow-fibre membrane or the hollow fiber conduit etc. that retention aperture is 0.2 ~ 3 micron.The material of film can be withIt is the similar hollow-fibre membrane such as polyether sulfone, regenerated cellulose, cellulose esters, modified poly (ether-sulfone).As plasma sample recovery approachCan not be also possible to cell retention effect but side have allow plasma sample by collect hole hollow tube.The material of hollow tubeIt can be the materials such as polysulfones, polypropylene, polytetrafluoroethylene (PTFE).
As a kind of specific embodiment of the invention, the LF-D23 glass fibre multi-hole filtering film of IWTremont is usedProduct uses 0.2 micron~1.0 microns of mPES hollow-fibre membrane as second level filter membrane as first order filter mediumAnd product recycling channel.Porous dielectric film can be punched into and use gear shape.There are apertures among gear shape diaphragm, as filtrateThe installation passage of collecting pipe.The side of tooth can be contacted with blood sample.Diaphragm can stack up and down, and the gear shape of adjacent diaphragms canTo be staggered up and down, to increase the contact area of gear parts upper and lower surface and blood sample.As secondary filtration and plasma collectionThe more hollow-fibre membranes and diaphragm in channel are vertical, and pass through the blood plasma to collect removal haemocyte among the diaphragm stacked.
In a kind of design, 15 millimeters of diaphragm gear shape outer diameter, 9 millimeters of solid disk diameter, the depth of gear teethAbout 3 millimeters of degree.Each diaphragm has 18 teeth.Pass through the hollow-fibre membrane of four 0.5 millimeter of internal diameters between in the filterPipe.4 centimetres of the diaphragm height stacked, the total number of plies of diaphragm are 120 layers.It is this to design average every film, including upper and lower surface, toothWheel side and end, and blood sample have the diaphragm area directly contacted to have 1 square centimeter or so.This 120 layers of porous media is formedFilter core in and the total filtering membrane area of blood sample contact can be about more than 100 square centimeters.
Filter core as described above is encapsulated in one in the shell of filter.The internal diameter (16~17 of filter housingMillimeter) it is slightly larger than the diameter of gear-like diaphragm.The cavity between gap and gear between gear and filter inner wall can be withThe channel flowed as blood sample and be distributed in filter.
At the top for the sheet-like filter medium that heap stacks, other piece of plastic cover plate can be placed.Outside cover plate and filterThere is 1~2 millimeter of gap between shell.Gap can enter the channel of porous filter core as blood sample.Placing porous mediaFilter disc when, in the absence of stress, the stack height of porous media can be slightly above the inner casing of filter.It is filteringDevice upper cover blood sample inlet tube can extend and have annulus outstanding, can withstand cover plate.To be compacted porous filter medium diaphragm.
The hollow-fibre membrane or doughnut tube cavity upper end port for collecting blood plasma are shut, fine in the lower hollow of filterDimension film inner cavity is connected to filter outlet, and the blood sample that haemocyte is removed after filtering converges to filter from each hollow fiber conduitOutlet.The outlet of filter can pass through standard luer fittings and syringe or piping connection.
There can be two parts composition in the external structure of filter.The upper cover and filter housing of filter, can pass throughSupersonic welding fetches sealing.Import and the blood plasma that the upper and lower part of filter housing has female Luer to do fresh blood sample respectivelyOutlet.Fig. 4 is shown in whole design.
Assembled filter can pass through gamma sterilization.In the case where needing 100% cell retention, can adoptWith hollow fiber membrane bundle as filtrate collection channel.The surface area of hollow-fibre membrane is bigger, and retention aperture is bigger, is more beneficial to fastThe cell filtration of speed.
Filter interior total volume is about 7~8 milliliters, and filter can always coprocessing blood sample be about 4~10 milliliters.According to specific experiment condition, 0.5~6 milliliter of blood plasma can be collected.
Embodiment 2
As another embodiment of the present invention, stacking mode of the structure of porous filter medium diaphragm in filter housingIt is similar to embodiment 1.Diaphragm can be two or more different circular films of diameter.There are receipts in the centre of circular filmThe hollow-fibre membrane or side that collect blood plasma have the hollow tube of plasma collection mouth.Two adjacent diaphragm diameters are not of uniform size, to increaseAdding can be with the surface area (such as Fig. 5) of the diaphragm of contacting blood.
If the diameter using two kinds of rounded porous medium diaphragms is respectively 15 millimeters and 9 millimeters.The diaphragm stacked4 centimetres of total height, the total number of plies of diaphragm is 120 layers.This design and the total filtering membrane area of blood sample contact can be more than 100Square centimeter.
Filter core as described above is encapsulated in a subcylindrical shell.The internal diameter of shell is 16~17 millimeters.
Hollow-fibre membrane inner cavity upper end port is shut, and lower end port is connected to filter outlet, and haemocyte is removed after filteringBlood sample the outlet of filter is converged to from each doughnut.Go out in filter outlet, space can be between hollow fiber conduitWith encapsulating polyurethane, to guarantee that blood will not short circuit and blood plasma mixing.The outlet of filter can by standard luer fittings andSyringe or piping connection.Fig. 5 is shown in whole design.
Filter interior total volume is about 7~8 milliliters, and filter can always coprocessing blood sample be about 4~10Milliliter.According to specific experiment condition, 0.5~6 milliliter of blood plasma can be collected.
Embodiment 3
As another specific embodiment of the invention.It is radial that porous coarse filtration medium cross-section can be designed as circular hollowThe diaphragm structure of structure (such as Fig. 6).The radial slot of diaphragm can be as the distribution channel of blood.The spoke of filter medium diaphragmThe side for penetrating shape slot can provide the area of blood and filter medium contact.The fluting of neighbouring diaphragm is staggered, to increase bloodThe contact area of liquid and porous media.In this configuration, new blood enters the central opening of filtration membrane, part haemocyteIt can be trapped in porous spongy filter medium face, remaining minority haemocyte can be trapped inside filter medium.FilterShell and porous media diaphragm between there are gaps.Gap between inner wall and filter medium can be used as the logical of blood plasma convergenceRoad.Gap can be formed by the second level filter membrane of folding.It is filtered by that can also be formed in filter housing inner wall flutingBlood plasma channel.The bottom enrichment of filter can be converged to by these channels through the blood plasma of filter.
Can there are shell and upper cover two parts to constitute in the structure of filter.Distinguish the upper and lower part of filter housingThere is connector to do the import of fresh blood sample and the outlet of blood plasma.In the basis rest porous filter screen of the shell of filter, strainer can be withAs the supporting layer of porous media, while nylon, polypropylene etc. can also be can be as the flow path of blood plasma, the medium of strainer.The bottom of filter can be completely covered in strainer.One layer of impermeable plastic sheet of strainer central upper portion position of sound production, for example take poly-Propylene material.This layer of plastic sheet precoat filter centre, the bottom of incomplete precoat filter, in plastic sheet and filteringThe gap of device inner casing can there are the filtration channel of blood plasma (such as Fig. 6).
As a kind of special case of the present embodiment.Use internal diameter for 10 millimeters of filter head housings, dish-shaped filter disc center is opened interior2 millimeters of bore dia.Diaphragm has radial fluting from center opening.Radial fluting can be rectangle, about 0.5 milli of widthRice, length are 3 millimeters, and each diaphragm can have 12 openings.The effective height of filter is 3 centimetres, effective filtration membrane90.The side of filter diaphragm fluting can be contacted with blood sample.Filter is provided with the face in this way in diaphragm fluting sideIf the diaphragm openings intersection of product about 23 square centimeters of this filters of is put, the region that diaphragm is not overlapped up and down can be withIt is contacted with blood sample.These diaphragm upper and lower surface and sample have the area of contact there are about 32 square centimeters.In filterThere are about 2~3 milliliters for volume.Can handle 2 milliliters or more of blood sample can obtain 0.2 milliliter or more of plasma sample.
Embodiment 4
As another specific embodiment of the invention.In the discharging modes of porous media piece, do not use multilayer folded up and downThe method stacked is acted, but discharge vertically.One way in which is as follows, and porous media filter can be cut into strip of sheet, filteringThe direction of medium slice is parallel with the axis of filter, and following and filtrate collection is vertical.Between silver can by silk screen orFilter is spaced apart by the other structures such as grid, forms gap to increase the contact area of porous media and blood sample.HereGap can be as the distributor of blood.Blood can flow from top to bottom from sheet-like filter medium gap, be distributed to porousDielectric surface.Blood plasma in blood can be entered inside spongy filter medium with lateral flow, and blood cell fraction is situated between in filteringThe surface of matter and the trapped inside of filter medium.It can be in porous media from top to bottom into the blood plasma inside porous filter mediumFlowing, and be enriched in the bottom of filter.In this configuration, it can be alternately arranged by the different filter disc of height, two phasesAdjacent higher filter disc is separated by silk screen or grid, forms new and contacting blood area.Blood can also pass through lower filter discTop enter filter.Under this porous media, there is support layer.This support layer can be porous strainer, orIt is the porous media that the planar diaphragm folded or other blood plasma can flow through, or the plasma collection in filter housing bottomThe side of slot.There is porous supporting layer under the filter discharged vertically or there can be secondary filter medium.This secondary filter is situated betweenMatter can be the plane filter membrane of folding.If the filter membrane in the aperture using 0.20 micron to 2.0 microns can retain blood completelyCell.If this is situated between for the porous media of filtrate receipt and the porous filtering of placement normal thereto only with porous mediaMatter can be same material, be also possible to different materials.(as shown in Figure 7)