Affinity binding-based system for detecting particulates in a fluid

• US 6,656,430 B2
• Filed: 11/20/2001
• Issued: 12/02/2003
• Est. Priority Date: 12/20/1996
• Status: Expired due to Fees

• Current Assignee: Tecan Trading AG (Tecan Group AG)
• Original Assignee: Tecan Trading AG (Tecan Group AG)
• Inventors: Sheppard, Norman F. Jr., Carvalho, Bruce L., Mian, Alec, Kellogg, Gregory, Kieffer-Higgins, Stephen G.
• Primary Examiner(s): Chin, Christopher L.
• Assistant Examiner(s): Do, Pensee T.
• Application Number:
  US09/989,259
• Publication Number:
  US 20020076804A1
• Time in Patent Office: 742 Days
• Field of Search: 422/63, 422/64, 422/68.1, 422/50, 422/72, 422/101, 422/102, 422/67, 436/45, 436/63, 436/177, 436/180, 210/787, 210/380.1, 210/374, 210/780, 210/109, 210/781, 435/7.1, 435/7.2, 435/7.21
• US Class Current: 422/63
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 35/71725 using centrifugal forces
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• 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 2300/021 Identification, e.g. bar codes
• CPC Class Codes: B01L 2300/024 Storing results with means integrated into the container
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2300/0806 Standardised forms, e.g. compact disc [CD] format
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/168 Specific optical properties, e.g. reflective coatings
• CPC Class Codes: B01L 2300/1805 Conductive heating, heat from thermostatted solids is conducted to receptacles, e.g. heating plates, blocks
• CPC Class Codes: B01L 2300/1861 using radiation
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0661 shape memory polymer valves
• CPC Class Codes: B01L 2400/0677 phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• CPC Class Codes: B01L 3/5027 : by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502715 : characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• 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 7/00 : Heating or cooling apparatus autoclaves B01J3/04; Heat insulating devices
• CPC Class Codes: C07K 14/79 : Transferrins, e.g. lactoferrins, ovotransferrins
• CPC Class Codes: C12N 9/2462 : Lysozyme (3.2.1.17)
• CPC Class Codes: G01N 15/14 : Optical investigation techniques, e.g. flow cytometry
• CPC Class Codes: G01N 21/07 : Centrifugal type cuvettes G01N21/09 takes precedence
• CPC Class Codes: G01N 33/54366 : Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/569 : for microorganisms, e.g. protozoa, bacteria, viruses
• CPC Class Codes: G01N 33/68 : involving proteins, peptides or amino acids involving lipoproteins G01N33/92
• CPC Class Codes: G01N 35/00069 : whereby the sample substrate is of the bio-disk type, i.e. having the format of an optical disk
• CPC Class Codes: Y10S 366/03 : Micromixers: variable geometry from the pathway influences mixing/agitation of non-laminar fluid flow
• CPC Class Codes: Y10T 436/111666 : Utilizing a centrifuge or compartmented rotor
• CPC Class Codes: Y10T 436/25375 : Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

This invention provides methods an apparatus for detecting and quantifying particulate matter suspended in a fluid. Specifically, the invention provides an integrated, affinity-binding based, analytical system comprising a platform for performing an affinity-binding based assay for specifically binding particulates including microbial cells, and a detection means for detecting the particulates specifically bound to a defined surface or chamber comprising the platform. Methods for using the analytical systems of the invention are also provided.

Claims

1. An apparatus for detecting a cell in a fluid, the apparatus comprising

a platform comprising a substrate having a surface, wherein said surface defines a cell accumulation chamber wherein a defined amount of a fluid comprising a cell is retained in the area for a time sufficient to permit the cell to accumulate in the area;

a fluid sample input means in fluid communication with the cell accumulation chamber;

an overflow reservoir in fluid communication with the fluid sample input means;

a wash buffer reservoir containing a wash buffer in fluid communication with the cell accumulation chamber;

a fluid waste receptacle in fluid communication with the cell accumulation chamber;

wherein an amount of a fluid sample comprising a cell is moved from the fluid sample input means to the cell accumulation chamber of the platform and incubated thereon for a time sufficient to permit the cell to accumulate in the area; and

wherein the fluid sample is replaced with the wash buffer and displaced into the fluid waste receptacle; and

wherein the wash buffer is further displaced into the fluid waste receptacle; and

wherein a cell in the cell accumulation chamber is detected thereupon.

2. The apparatus of claim 1, wherein the sample input means comprises an area on said first surface, wherein a metered amount of an unmetered fluid sample applied to the surface is retained in the fluid sample input means, wherein fluid comprising the unmetered fluid sample in excess of the metered amount of the fluid sample that is retained in the fluid sample input means is retained in the overflow reservoir on the surface of the platform.

3. An apparatus according to claim 1 wherein the cell accumulation chamber further comprises a filtering means having a pore size that prevents the cells from leaving the cell accumulation chamber.

4. An apparatus according to claim 1 wherein the surface is modified to permit the cell to attach to the surface and be retained in the cell accumulation chamber thereby.

5. An apparatus according to claim 1 wherein each of the components of the apparatus in fluid communication with one another are connected by a plurality of microchannels that enable fluid communication between the components of the apparatus.

6. An apparatus according to claim 1 wherein the cell accumulation chamber further comprises a non-specific cell adhesion means that prevents the cells from leaving the cell accumulation chamber.

7. An apparatus according to claim 1, further comprising:

a label reservoir comprising an amount of a detectable labeling moiety that is specific for the particulate to be detected and is in fluid communication with the cell accumulation chamber, wherein the wash buffer is displaced from the cell accumulation chamber by the detectable labeling moiety.

8. An apparatus according to claim 7, wherein the detectable labeling moiety is a histochemical stain.

9. An apparatus according to claim 7 wherein the detectable labeling moiety is a immunochemical reagent.

10. An apparatus according to claim 9 wherein the immunochemical reagent is a detectably labeled antibody.

11. An apparatus according to claim 10 wherein the detectable label is a fluorescent label.

12. An apparatus according to claim 10 wherein the detectable label is produced by an enzymatic moiety, wherein the apparatus further comprises a substrate for the enzymatic moiety wherein the substrate is converted to a detectable label by enzymatic action.

13. An apparatus according to claim 12 wherein the substrate is a component of the wash buffer.

14. An apparatus according to claim 1 wherein the wash buffer further comprises a detectable label.

15. An apparatus according to claim 1 wherein the cell accumulation chamber comprises a volume from about 5 μ

L to about 1000 μ

L.

16. An apparatus according to claim 1 for measuring an effect of a test compound on a cell, the apparatus further comprising

a reagent reservoir containing a test compound in fluid communication with the cell accumulation chamber of the platform;

wherein an amount of a fluid sample comprising a cell is moved from the fluid sample input means to the cell accumulation chamber of the platform and incubated thereon for a time sufficient to permit the cell to accumulate in the area; and

wherein the fluid sample is replaced with the test compound and incubated thereon for a time sufficient for the test compound to have an effect on the cell in the cell accumulation chamber; and

wherein the effect of the test compound on the cell in the cell accumulation chamber is assayed by visual inspection and is detected thereby.

17. The apparatus of claim 16 wherein the effect is cytotoxicity and is detected by a reduction of cell viability in the presence of the test compound.

18. The apparatus of claim 16 wherein the effect is cell activation comprising binding to a cellular receptor and is detected by a difference in intracellular ion concentrations in the presence and absence of the test compound.

19. An apparatus according to claim 18 wherein each of the components of the apparatus in fluid communication with one another are connected by a plurality of microchannels that enable fluid communication between the components of the apparatus.

20. An apparatus according to claim 16, further comprising:

a reservoir comprising an amount of a detectable labeling moiety that is specific for viable cells, wherein the test compound is displaced from the cell accumulation chamber of the platform the detectable labeling moiety.

21. An apparatus according to claim 20, wherein the detectable labeling moiety is a histochemical stain, a fluorescent ion indicator, a electric potential-sensitive indicator dye or an ion-sensitive indicator dye.

22. An apparatus according to claim 20 wherein the detectable labeling moiety is a immunochemical reagent.

23. An apparatus according to claim 22 wherein the immunochemical reagent is a detectably labeled antibody.

24. An apparatus according to claim 23 wherein the detectable label is a fluorescent label.

25. An apparatus according to claim 23 wherein the detectable label is produced by an enzymatic moiety, wherein the apparatus further comprises a substrate for the enzymatic moiety wherein the substrate is converted to a detectable label by enzymatic action.

26. An apparatus according to claim 16 wherein a portion of the cell accumulation chamber is optically transparent.

27. An apparatus according to claim 16 further comprising a device, wherein the device has a surface or cavity that accommodates the platform;

and a light source positioned to illuminate the platform.

28. An apparatus according to claim 27 further comprising a photodetector, wherein the photodetector is positioned to detect light from the light source transmitted through or reflected from the cell accumulation chamber on the platform surface.

29. An apparatus according to claim 28 wherein a portion of the cell accumulation chamber is optically transparent, and the photodetector and the light source are positioned so that light from the light source illuminates the cell accumulation chamber and is detected by the photodetector through the optically transparent portion of the platform.

30. An apparatus according to claim 28 wherein a portion of the cell accumulation chamber comprises a reflective surface, and the photodetector and the light source are positioned so that light from the light source illuminates the cell accumulation chamber, is reflected therefrom and the reflected light is detected by the photodetector.

31. An apparatus according to claim 27 wherein the detection chamber on the platform further comprises alternating transparent and reflective regions.

32. An apparatus according to claim 31, wherein the alternating transparent and reflective regions define a pattern in the area.

33. An apparatus according to claim 31 wherein the specific binding reagent is present in the detection chamber on a transparent region thereof.

34. An apparatus according to claim 16 wherein the metered amount of the fluid sample is from about 10 μ

L to about 500 μ

L.

35. An apparatus according to claim 16 wherein the cell accumulation chamber further comprises a filtering means having a pore size that prevents the cells from leaving the cell accumulation chamber.

36. An apparatus according to claim 16 wherein the cell accumulation chamber further comprises a non-specific cell adhesion means that prevents the cells from leaving the cell accumulation chamber.

37. An apparatus according to claim 16 wherein the surface is modified to permit the cell to attach to the surface and be retained in the cell accumulation chamber thereby.

38. A method for measuring an effect of a test compound on a cell using an apparatus according to claim 16, the method comprising the steps of:

applying an amount of a sample to the fluid sample input means of the apparatus;

moving the fluid sample from the fluid sample input means to the cell accumulation chamber;

incubating the fluid sample in the cell accumulation chamber and replacing the fluid of the fluid sample in the cell accumulation chamber with the wash buffer, wherein the cells are retained in the cell accumulation chamber;

replacing the fluid sample with the test compound in the cell accumulation chamber, wherein the cells are retained in the cell accumulation chamber;

incubating the cells in the presence of the test compound for a time sufficient for the test compound to have an effect on the cell in the cell accumulation chamber;

detecting the effect of the test compound on the cell in the cell accumulation chamber.

39. A method for detecting a cell in a fluid using an apparatus according to claim 1, the method comprising the steps of:

applying an amount of a sample to the fluid sample input means of the apparatus;

moving the fluid sample from the fluid sample input means to the cell accumulation chamber;

incubating the fluid sample in the cell accumulation chamber and replacing the fluid of the fluid sample in the cell accumulation chamber with the wash buffer, wherein the cells are retained in the cell accumulation chamber;

displacing the wash buffer into the fluid waste receptacle, wherein the cells are retained in the cell accumulation chamber; and

detecting the particulate retained in the cell accumulation chamber.