US20140374299A1 - Micro-vials - Google Patents

Abstract

A simple, low cost, efficient and stable micro-vial configuration for handling micro-volume of sample fluids. The interior wall geometry of the inventive vial is designed to include several axial sections of various interior diameters to provide a range of functionalities to address various design considerations. The interior wall defined in the vial has a cylindrical sample section, a wider cylindrical alignment section, a tapered or conical guide section, and a relatively large cylindrical body section, arranged in sequence in that order along the center axis of the vial. The sample section is designed to hold a small volume of a sample fluid, and to receive the tip end of a capillary tube. The alignment section has a larger diameter than the sample section, designed to receive a cylindrical support that coaxially supports the relatively fragile capillary tube. The tip of the capillary tube dips into the micro-volume of sample fluid held in the sample section. The conical section functions to guide the capillary tube and the support tube into the alignment section and the tip of the capillary tube into the sample section. The body section has the largest diameter, for holding additional fluid if desired.

Description

PRIORITY CLAIM
• This application claims the priority of U.S. Provisional Patent Application No. 61/838,791 filed on Jun. 24, 2013; this application is also a continuation of U.S. Patent Application No. 29/458,922 filed on Jun. 24, 2013, which are fully incorporated by reference as if fully set forth herein. All publications noted below are fully incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention is directed to receptacles for holding fluid for bio-analysis, and more particularly to vials for holding small volumes of fluids.
• 2. Description of Related Art
• DNA sequencing is a type of bio-analysis, involving the process of determining the precise order of nucleotides within a DNA molecule. It includes any method or technology that is used to determine the order of the four bases—adenine, guanine, cytosine, and thymine—in a strand of DNA. The advent of rapid DNA sequencing methods has greatly accelerated biological and medical research and discovery.
• Knowledge of DNA sequences has become indispensable for basic biological research, and in numerous applied fields such as diagnostic, biotechnology, forensic biology, and biological systematics. The rapid speed of sequencing attained with modern DNA sequencing technology has been instrumental in the sequencing of complete DNA sequences, or genomes of numerous types and species of life, including the human genome and other complete DNA sequences of many animal, plant, and microbial species.
• Next-generation sequencing (NGS) has revolutionized the genetic landscape, It is a lengthy, labor-intensive process that yields results never before achieved, As a result, it is imperative that the quality of the sample be evaluated from the start, as most NGS sample preparation protocols require PCR amplification to generate DNA libraries prior to sequencing.
• The likelihood of artifact generation could contribute to bias, affecting the potential results. High sensitivity DNA analysis has been optimized with the improved capillary gel electrophoresis detection systems developed by the assignee of the present invention, &Optic, Inc. (see, U.S. Patent Application Publication Nos. US2011/0253540A1 and 2012/0168312A1; and, for example, the Qsep100 instrument developed by BiOptic, Inc.). Improved sensitivity allows the numbers of library PCR cycles to be reduced, removing amplification bias and significantly improving the quality of NGS data with increased accuracy.
• Since relatively large volumes (e.g., in the order of 20 to 40 micro-liters) of PCR products are necessary/needed to be used in sequencing type instruments, and the sequencing sample preparation process is costly, preferably a small volume of PCR product is sampled for screening quickly (e.g., through gel-electrophoresis or capillary electrophoresis) to make sure there is enough PCR product present (detected) in the PCR products before proceeding with the full sequencing process (DNA analysis). This involves injecting a small volume of sample PCR product into the tip of a capillary tube, to allow the sample to undergo electrophoresis through the capillary tube. It is desired to sample as small a volume of PCR product as possible, so as to leave more PCR products available for subsequent sequencing.
• It has always been a challenge in the field to try to contain a small volume of fluid in micro volume in the order of several micro-liters in a receptacle, and in particular in a manner to provide access to sample by a capillary tube.
SUMMARY OF THE INVENTION
• The present invention provides a simple, low cost, efficient and stable micro-vial configuration for handling micro-volume of sample fluids, which overcomes the drawbacks of the prior art. Accordingly to the present invention, the internal wall geometry of the inventive vial is designed to include several axial sections of various interior diameters to provide a range of functionalities to address various design considerations. The interior wall defined in the vial has a cylindrical sample section, a wider cylindrical alignment section, a tapered or conical guide section, and a relatively large cylindrical body section, arranged in sequence in that order along the center axis of the vial.
• The sample section has the smallest diameter of all the sections, designed to hold a small volume of a sample fluid (e.g., in the order of less than 5 micro-liters, preferably 1 to 2 micro liters), and to receive the tip end of a capillary tube. The alignment section has a larger diameter than the sample section, designed to receive a cylindrical support that coaxially supports the relatively fragile capillary tube. The support may be a metal tube, which extends from a capillary cartridge and functions as a tube-shaped electrode for such cartridge. The capillary tube is threaded through the bore of the support tube, and the tip of the capillary tube extends beyond and is exposed from the end of the support tube. The tip of the capillary tube dips into the micro-volume of sample fluid held in the sample section. The conical section functions to guide the capillary tube and the support tube into the alignment section and the tip of the capillary tube into the sample section. The body section has the largest diameter. The vial thus has the capacity to hold a relatively large volume of fluid, which can fill the body section.
BRIEF DESCRIPTION OF THE DRAWINGS
• For a fuller understanding of the nature and advantages of the invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings. In the following drawings, like reference numerals designate like or similar parts throughout the drawings.
• FIG. 1 is a perspective view of a strip of micro-vials in accordance with one embodiment of the present invention;
• FIG. 2 is a front view thereof (the rear view is a mirror image of the front view);
• FIG. 3 is a right side view thereof (the left side view is a mirror image of the right side view);
• FIG. 4 is a top plan view thereof;
• FIG. 5 is a bottom plan view thereof; and
• FIG. 6 is a sectional view of a micro-vial taken along line6-6 inFIG. 4, showing interior structure, wherein each micro-vial has a similar interior structure.
• FIG. 7 is a perspective view of a strip of micro-vials with broken lines depicting a strip of micro-vials of indefinite number of vials, in accordance with one embodiment of the present invention (i.e., the inventive concept is not limited to the specific number of micro-vials link together).
• FIG. 8 is a front view thereof (the rear view is a mirror image of the front view);
• FIG. 9 is a right side view thereof (the left side view is a mirror image of the right side view);
• FIG. 10 is a top plan view thereof;
• FIG. 11 is a bottom plan view thereof; and
• FIG. 12 is a sectional view of a micro-vial taken along line12-12 inFIG. 10, showing interior structure, wherein each micro-vial has a similar interior structure.
• FIG. 13 schematically illustrates access of the micro-vials by an external device.
• FIG. 14 is an enlarged view of the access of sample solution in a micro-vial.
• FIG. 15 is a pictorial view showing access of sample solution in a single micro-vial.
• FIG. 16 is a top view of a strip of micro-vials, providing dimensions in accordance with one embodiment of the present invention.
• FIG. 17 is a side view of the strip ofFIG. 16, providing additional dimensions, in accordance with one embodiment of the present invention.
• FIG. 18 is a sectional view taken along line A-A inFIG. 17, providing additional dimensions, in accordance with one embodiment of the present invention.
• FIG. 19 is another sectional view taken along line A-A inFIG. 17, providing additional dimensions, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• This invention is described below in reference to various embodiments with reference to the figures. While this invention is described in terms of the best mode for achieving this invention's objectives, it will be appreciated by those skilled in the art that variations may be accomplished in view of these teachings without deviating from the spirit or scope of the invention.
• The inventive micro-vial is described in connection with the embodiment of sample injection and detection technique in bio-analysis, particularly micro-volume sample injection, separation and detection through a micro-capillary channel, and more particularly a capillary tube supported in a gel capillary cartridge (e.g., developed by BiOptic, Inc.). The inventive micro-vial is especially useful for pre-screening of PCR DNA products prior to Next Generation Sequencing applications. The inventive micro-vial can be adapted for use with other bio-analysis tools, instruments and systems, in connection with other bio-analysis processes, which is well within the scope and spirit of the present invention.
• The present invention provides a simple, low cost, efficient and stable micro-vial configuration for handling micro-volume of sample fluids, e.g., for injection into a capillary column for bio-separation (e.g., capillary electrophoresis for detection of PCR products (i.e., DNA sample)).
• Referring to the embodiment shown inFIGS. 1-6, themicro volume vials10 can be configured in astrip12 of N vials (wherein N is at least 1, but can be 8, 12, or any desired number). Referring toFIGS. 7-12, an alternate embodiment is shown with broken lines to depict astrip12′ having at least twovials10, but the number of vials may be indefinite, or of any number. Further, instead of a strip of a plurality ofvials10, it is well within the present invention to configure separate single vials10 (see, e.g.,FIG. 15, depicting a single vial10). Further, instead of strips, thevials10 may be defined as wells in a block or plate (i.e., a 96-well micro-titer plate having wells defined with the interior wall geometry of thevial10 disclosed here).
• Specifically, adjacent vials are connected at the opening area by atap14. Ahandle19 is provided at each end of thestrip12. In one embodiment, the center spacing between vials may be configured to correspond to the format of an industry standard 96-well (8×12) micro-titer plate.Several strips12 of vials may be assembled to form a tray of wells, e.g., resembling a 96-well titer plate, by using an appropriate holder or bracket (not shown).
• Referring to the sectional views inFIGS. 6 and 12, thevial10 has an external geometry which is not critical to the function of micro-volume fluid handling. In this regards, thevial10 may be configured with a relatively large external body (e.g., a block having interior walls defining the interior wall geometry of the vial) for easier handling by a user. Accordingly to the present invention, the internal wall geometry of eachvial10 is designed to include several axial sections of various interior diameters to provide a range of functionalities to address various design considerations. Referring also to the pictorialFIG. 15, the interior wall defined in thevial10 has acylindrical sample section20, acylindrical alignment section22, a tapered orconical section24, and acylindrical body section26, arranged in sequence in that order along thecenter axis18 of the vial.
• Thesection20 has a cylindrical section with a bottom, and has the smallest diameter of all the sections, designed to hold a small volume of a sample fluid30 (e.g., in the order of less than 5 micro-liters, preferably 1 to 2 micro liters), and to receive the tip end of a capillary tube32 (e.g., about 0.350-400 mm overall external diameter, including cladding or protective coating on the silica capillary tube32).
• Thealignment section22 has a larger diameter thansection20, designed to receive acylindrical support34 that coaxially supports the relatively fragilecapillary tube32. The support may be a metal tube (e.g., about 1 mm outside diameter, with a bore having an inner diameter of about 0.5 mm internal diameter to receive the capillary tube32), which extends from acapillary cartridge38 and functions as a tube-shapedcathode34 for such cartridge28, as shown inFIG. 15 (see BiOptic's capillary cartridge and analysis system discussed in U.S. Patent Application Publication Nos. US2011/0253540A1 and 2012/0168312A1). Thecapillary tube32 is threaded through thesupport tube34, and the tip of thecapillary tube32 extends beyond and is exposed from the end of thesupport tube34. As shown inFIG. 15, the tip of thecapillary tube32 dips into the sample fluid insection20.
• Theconical section24 provides a tapered wall surface to guide thecapillary tube32 and thesupport tube34 into thealignment section22 and the tip of thecapillary tube32 into thesection20.
• Thebody section26 has an opening, and the largest diameter of the wall sections. Thevial10 thus has the capacity to hold a relatively large volume of fluid, which can fill thebody section26.
• Amineral oil36 may be provided to fill the space above the sample fluid in thesection20, to prevent evaporation of the small volume of sample fluid. Themineral oil36 may fill thealignment section22 and/or theconical section24 and/or thebody section26.
• Referring toFIGS. 16-19, exemplary dimensions of astrip12 ofvials10 are provided, in accordance with one embodiment of the present invention. All dimensions shown inFIGS. 16-19 are in mm unit, unless otherwise stated.
• The above described micro-vials10 and strips12 may be made of materials including glass, metal, plastic, rubber, silicon, etc., preferably of a chemically inert material that is inert to reacting with the fluid intended to be held in thevials10. Thevials10 and/or strips12 may be formed by etching (e.g., of a semiconductor material such as a silicon substrate), stamping (e.g., of a metal or plastic), or molding (e.g., plastic or rubber injection molding). Further, thevials10 andstrip12 may be made of different materials, which may be fused together to form thestrip12. The wall structure of the vials may be made of a certain material and the interior wall of thevials10 may be lined with a chemically inert material.
• Using the inventive vial for handling a micro volume of sample fluid, it is possible to develop bio-analysis systems that are significantly small in overall size (see, e.g., BiOptic'sQsep100 instrument). Miniaturization of analytical instrumentation has many advantages over conventional systems and techniques. These advantages include improved data precision and reproducibility, short analysis times, minimal sample consumption, improved automation and integration of complex workflows.
• In one embodiment, an injection-moldedvial10 can accommodate a small volume of 1 to 2 micro-liters (e.g., of PCR DNA Sample to be injected electro-kinetically using Capillary Gel Electrophoresis (CGE) for pre-screening and quality control (qualitative and quantitative). The micro-vials are injection molded in strips of 8-vials or 12-vials and can be directly inserted inside the BiOptic's CGE system (Qsep100) Sample Tray to interface the Pen-Shaped Gel-Cartridge for sample intake through the automated sample tray. Reference is made to BiOptic's capillary cartridge and analysis system discussed in U.S. Patent Application Publication Nos. US2011/0253540A1 and 2012/0168312A1).
• According to the micro-vial design geometry of the present invention, it facilitates sample injection in micro-liter volume of 1 to 2 micro-liters. Thealignment section22 of thevial10 allows the gel-cartridge electrode (cathode tube34 inFIG. 15) with supportedcapillary tube32 to be inserted and aligned accurately for sample intake at thesample holding section20.
• The access of sample held in thevial10 by acartridge38 is schematically shown inFIGS. 13,14 and15. Referring to BiOptic's Qsep100 DNA analyzer, thecartridge38 is supported on a stand50 (schematically shown inFIG. 13), and a robotic mechanism52 (schematically shown inFIG. 13) moves the sample tray supporting thevials10 relative to the tip of thecapillary tube32 supported in thecartridge38. The cathode tube34 (which coaxially supports the capillary tube32) in thecartridge38 may be aligned automatically by the sample tray mechanism, with the conical taperedsection24 of thevial10 guiding entry ofcathode tube34 inside thealignment section22, which has an internal diameter (e.g., 1.75 mm) that is close to the outside diameter of the cathode tube34 (1 mm). Referring toFIGS. 14 and 15, as thecathode tube34 is further inserted inside thevial10, the tip of thecapillary tube32 is guided and aligned to ensure contact with the test or sample solution30 (e.g., DNA sample).
• One micro-liter of test solution can be placed in thesample section20 inside thevial10 by using, for example, a standard handheld pipette. Since small air-bubbles could be introduced during sample deposition by the pipette, it is recommended to spin (centrifuge) the vial10 (e.g., theentire strips12 before further processing (in much the same way a standard 96-well microtiter plate is centrifuged). It is also recommended to apply a small amount of mineral oil to prevent sample evaporation and facilitate multiple consecutive sample injections.
• Thevials10 are designed to be single unit, or in 8 and/or 12-strips, or could be molded to be 96-vial or 384-vial format. Thevials10 can be used with other capillary electrophoresis, HPLC or micro-fluidic type products (from different manufacturers) that have capillary based cartridge, in which the capillary is supported by a metal, plastic, ceramic or other outside jacket/electrode.
• In Summary, the inventive micro-vial achieve one or more of the following advantages:
• The inventive micro-vial allows handling of 1 to 2 micro-liter volume of sample (e.g., PCR DNA sample) to be allocated inside the vial to be interfaced with a capillary based cartridge for automated sample injection.
• By applying a drop of mineral oil over the 1 to 2 micro-liters of sample inside the micro-vial, o ne can do multiple sample injections (electro-kinetically) into the pen-shaped gel-cartridge. The mineral oil prevents sample evaporation, and due to conductive properties, it also facilitates multiple injections.
• The inventive strips of vials (e.g., injection molded strips) may be either in a strips of 8 or 12 vials, conforming to industry standard formats, which allows the strips to be expanded to 96-vial and/or 384-vial formats, if desired.
• The inventive micro-vial design allows small consumption of DNA products (gDNA) to be sample for quality control prior to qPCR or Sanger Sequencing analysis, or for post-PCR sample analysis using capillary electrophoresis-based DNA fragment analyzers.
• The inventive micro-vial design provides flexibility for automated sample injection in CGE based instruments.
• The inventive micro-vial design provides robust and reproducible sample injections, resulting in accurate analysis results with better integrity.
• While the invention has been particularly shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit, scope, and teaching of the invention. Accordingly, the disclosed invention is to be considered merely as illustrative and limited in scope only as specified in the appended claims.

Claims (12)

We claim:

1. A vial for holding a micro-volume of fluid, comprising:

a body defining an interior wall, the wall comprising a cylindrical sample section having a bottom, a wider cylindrical alignment section, a conical guide section, and a relatively large cylindrical body section having an opening, arranged in sequence in that order along a center axis of the body.

2. The vial as inclaim 1, wherein the sample section has a cylindrical section that is sized to receive a tip of a capillary tube and to hold a micro-volume of fluid.

3. The vial as inclaim 2, wherein the cylindrical section of the sample section has an internal diameter of about 0.5 mm, receiving the tip of the capillary tube having an outside diameter of similar size.

4. The vial as inclaim 1, wherein the micro-volume is in the order of less than 5 micro-liters.

5. The vial as inclaim 4, wherein the micro-volume is in the order of 1 to 2 micro liters.

6. The vial as inclaim 2, wherein the alignment section has a larger diameter than the sample section, sized to receive a cylindrical support that coaxially supports the capillary tube.

7. The vial as inclaim 6, wherein the cylindrical support is a tube, through which the capillary tube extends with the tip beyond an end of the tube to dip into the micro-volume of fluid held in the sample section.

8. The vial as inclaim 7, wherein the conical guide section provides a tapered wall surface to guide the capillary tube and the support tube into the alignment section and the tip of the capillary tube into the sample section.

9. The vial as inclaim 8, wherein the body section has the largest diameter compared to the other sections of the body, for containing a relatively large volume of fluid.

10. The vial as inclaim 9, wherein the body is injection molded plastic.

11. A strip of vials for holding micro-volumes of fluid, comprising a plurality of N (N>0) vials in which adjacent vials are connected by a tab, each vial having a structure as inclaim 1.

12. The strip of vials as inclaim 11, wherein N is equal to 8 or 12.

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