Disposable unit in diagnostic assays

• US 5,399,486 A
• Filed: 02/18/1993
• Issued: 03/21/1995
• Est. Priority Date: 02/18/1993
• Status: Expired due to Fees

• Current Assignee: Biocircuits Corporation
• Original Assignee: Biocircuits Corporation
• Inventors: Schwartz, Henry L., Cathey, Cheryl A.
• Primary Examiner(s): Kepplinger, Esther M.
• Assistant Examiner(s): PRESTON, DAVID
• Application Number:
  US08/019,469
• Time in Patent Office: 761 Days
• Field of Search: 435/7.1, 435/7.2, 435/7.92, 435/7.93, 435/7.94, 435/7.95, 436/501, 436/518, 436/519, 436/537, 422/55, 422/58, 422/63
• US Class Current: 435/7.9
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: G01N 2035/00267 Meltable plugs
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing

Abstract

A disposable diagnostic unit is provided which employs a housing which provides for a sample port, and a channel which feeds the sample to an incubation area by means of capillary action. The incubation area is underneath an optically-clear window and comprises a lipid membrane which has optical properties, particularly fluorescent properties and usually a reagent. A reservoir at the end of the channel downstream from the incubation area receives the sample and waste washes, while on one side of the platform area is a reagent reservoir and on the other side a side waste reservoir, so that one can move the reagent from the reagent reservoir through the platform area into the waste reservoir. Various reagents may be contained within the unit and the necessary liquids added automatically by appropriate instrumentation, so as to have the assay carried out automatically, without technician involvement, providing an accurate and sensitive determination.

Claims

1. A diagnostic disposable device comprising:

a housing;

said housing containing as assay system comprising;

within said housing, a fluorescent lipid membrane;

an incubation area in said housing, having opposing walls;

a first fall supporting said fluorescent lipid membrane;

a second wall supporting a reagent, said walls being spaced apart to provide for capillary flow through said incubation area, wherein said reagent specifically binds to a specific binding pair member proximal to one face of said fluorescent lipid membrane;

proximal to one end of said housing, a sample port;

a capillary channel connecting said incubation area to said sample port;

side reservoirs on each side of said incubation area, said side reservoirs being a reagent storage reservoir and a waste reservoir, and a main waste receiving reservoir downstream from said incubation area opposite from said channel, said main waste and side reservoirs having gas release ports, side reagent storage reservoir having an inlet port; and

an optically clear window over said fluorescent lipid membrane.

2. A diagnostic disposable device according to claim 1, wherein the side walls of said side reservoirs extending from said second wall drop steeply down to substantially reduce capillary force.

3. A diagnostic disposable device according to claim 1, wherein said housing has a trough, an inlet port and a gas release port for said trough, unconnected with said assay system, wherein said trough serves for receiving priming or other waste fluid and is in a fluid collecting and filling relationship with said assay system.

4. A diagnostic disposable device according to claim 1, wherein the depth of said main waste reservoir increases distal from said incubation area.

5. A diagnostic disposable device comprising:

a housing;

said housing comprising a top plate and a bottom plate fastened together, one plate having detents and the other plate having orifices for indexing said plates;

said housing containing an assay system comprising;

within said housing, a fluorescent lipid membrane;

an incubation area in said housing, having opposing walls;

a first wall supporting said fluorescent lipid membrane;

a second wall supporting a reagent, said walls being spaced apart to provide for capillary flow through said incubation area, wherein said reagent specifically binds to a specific binding pair member proximal to one face of said fluorescent lipid membrane;

proximal to one end of said housing, a sample port;

a capillary channel connecting said incubation area to said sample port;

reservoirs on each side of said incubation area, said side reservoirs being a reagent storage reservoir and a waste reservoir, and a main waste receiving reservoir downstream from said incubation area opposite from said channel, said main waste and side waste reservoirs having gas release ports, said side reagent storage reservoir having an inlet port, said gas release port being slots extending along one side of said reservoirs, wherein the side walls of said side reservoirs extending from said second wall drop steeply down to substantially reduce capillary force; and

an optically clear window over said fluorescent lipid membrane.

6. A diagnostic disposable device according to claim 5, wherein the side wall of said reagent storage reservoir is at an angle of about 90°

and said side wall of said side waste reservoir is at an angle of about 50°

.

7. A diagnostic disposable device according to claim 5, wherein said reagent is an enzyme conjugate and said side reagent storage reservoir contains enzyme substrate.

8. A diagnostic disposable device according to claim 5, wherein said housing comprises a plurality of assay systems.

9. A diagnostic disposable device according to claim 5, wherein said housing has a trough, an inlet port and a gas release port for said trough, unconnected with said assay system, wherein said trough serves for receiving priming or other waste fluid and is in a fluid collecting and filling relationship with said assay system.

10. A diagnostic disposable device according to claim 5, wherein the depth of said main waste reservoir increases distal from said incubation area.

11. A diagnostic disposable device according to claim 5, wherein said plates are made of a moldable plastic and said plates are welded together.

12. A method for determining an analyte in a sample comprising:

providing a disposable diagnostic device comprising;

a housing;

said housing containing an assay system comprising;

an incubation area in said housing, having opposing walls;

a first wall supporting a fluorescent lipid membrane having a first member of a specific binding pair of Which said analyte is a member proximal to an exposed surface of said membrane and a second wall supporting an enzyme conjugate reagent capable of binding to said first member in proportion to the amount of analyte in said sample, said walls being spaced apart to provide for capillary flow through said incubation area;

proximal to one end of said housing a sample port;

a capillary channel connecting said incubation area to said sample port;

reservoirs on each side of said incubation area, said side reservoirs being a reagent storage reservoir for storing enzyme substrate and a waste reservoir, and a main waste receiving reservoir downstream from said incubation area opposite from said channel, said main waste and side waste reservoirs having gas release ports, side reagent storage reservoir having an inlet port; and

an optically clear window over said fluorescent lipid membrane;

adding sample to the sample port of said diagnostic device, whereby said sample is transported through the capillary channel into said incubation area;

allowing said sample to move through said incubation area into a main waste reservoir downstream from said incubation area, whereby said enzyme conjugate is dissolved and specifically binds to the first members on said fluorescent lipid membrane in proportion to the amount of analyte present in said sample;

introducing wash solution into said sample port, whereby said wash solution washes said incubation area substantially free of sample components and unbound enzyme conjugate;

introducing a buffer solution into a side reagent storage reservoir to dissolve said enzyme substrate and transport said enzyme substrate through said incubation area into the side waste reservoir, whereby enzyme product is produced Which modulates the fluorescence of said fluorescent lipid membrane;

irradiating said fluorescent lipid membrane through said optically clear window, whereby said lipid membrane is excited and fluoresces; and

measuring the fluorescence intensity at at least one time to determine the presence of analyte in said sample.

13. A method according to claim 12, wherein said analyte is a hapten.

14. A method according to claim 12, wherein said analyte is an antigen.

15. A method according to claim 12, wherein said analyte and said enzyme conjugate are competitive in binding to the first member on said fluorescent lipid layer.

16. A method according to claim 12, wherein said analyte specifically binds both the first members on said fluorescent lipid membrane and said enzyme conjugate.

17. A diagnostic disposable device comprising:

a housing for use in an assay for determining an analyte;

said housing containing a plurality of areas for providing different functions associated with said assay;

an incubation area having spaced apart walls to provide for capillary flow through said incubation area;

proximal to one end of said housing, a sample port;

a capillary channel connecting said incubation area to said sample port;

side reservoirs on each side of said incubation area, said side reservoirs being a reagent storage reservoir and a waste reservoir, and a main waste receiving reservoir downstream from said incubation area opposite from said channel, said main waste and side waste reservoirs having gas release ports, with said reagent storage reservoir having an inlet port to allow for flow of liquid orthogonal to the direction defined by said capillary channel;

an optically clear window over said incubation area.

18. A diagnostic disposable device according to claim 17, wherein said ports are slot-shaped.