Method for performing counts within a biologic fluid sample

• US 8,158,434 B2
• Filed: 04/27/2010
• Issued: 04/17/2012
• Est. Priority Date: 10/19/2005
• Status: Active Grant

• Current Assignee: Abbott Laboratories Incorporated
• Original Assignee: Abbott Laboratories Incorporated
• Inventors: Wardlaw, Stephen C.
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Turk, Neil N
• Application Number:
  US12/767,916
• Publication Number:
  US 20100272345A1
• Time in Patent Office: 721 Days
• Field of Search: None
• US Class Current: 436/63
• CPC Class Codes: B01L 2200/0684 Venting, avoiding backpressure, avoid gas bubbles
• CPC Class Codes: B01L 2300/0822 Slides
• 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 3/508 rigid containers not provided for above
• CPC Class Codes: G01N 15/1433 using image recognition
• CPC Class Codes: G01N 2015/012 Red blood cells
• CPC Class Codes: G01N 2015/016 White blood cells
• CPC Class Codes: G01N 2015/018 Platelets
• CPC Class Codes: G01N 2015/1486 Counting the particles
• CPC Class Codes: G02B 21/34 Microscope slides, e.g. mounting specimens on microscope slides
• CPC Class Codes: Y10T 436/101666 Particle count or volume standard or control [e.g., platelet count standards, etc.]

Abstract

A method for enumerating cellular elements and particulates within a biologic fluid sample is provided. According to one aspect of the invention, the method includes the steps of: a) providing a chamber formed between a first planar member that is transparent and a second planar member, which members are separated from one another by a substantially uniform height, and which chamber has a known volume; b) introducing the biologic fluid sample into the chamber in an amount such that the sample extends between the first and second members for substantially the entire extent of the chamber, which fluid sample has first cellular elements having a first thickness and second cellular elements having a second thickness; c) selecting the chamber height relative to the first and second thicknesses such that the first and second cellular elements non-uniformly distribute within the sample upon introduction into the chamber; d) examining substantially all of the sample within the chamber and enumerating all of at least one of the elements; and e) determining a number per unit volume of sample of the at least one of the elements.

Claims

1. A method for enumerating cellular elements within a biologic fluid sample, comprising the steps of:

providing a chamber formed between a first planar member that is transparent and a second planar member, which members are separated from one another by a substantially uniform height, and which chamber has a known volume;

introducing the biologic fluid sample into the chamber in an amount such that the sample extends between the first and second members for substantially the entire extent of the chamber, which fluid sample has first cellular elements having a first thickness and second cellular elements having a second thickness;

selecting the chamber height relative to the first and second thicknesses such that the first and second cellular elements non-uniformly distribute within the sample upon introduction into the chamber;

examining substantially all of the sample within the chamber in an unlysed state and enumerating all of at least one of the first and second cellular elements non-uniformly distributed within the chamber; and

determining a number per unit volume of sample of the at least one of the cellular elements.

2. The method of claim 1, wherein the biologic fluid sample is anticoagulated whole blood.

3. The method of claim 2, wherein the steps of examining and determining the number utilize digital image analysis.

4. The method of claim 3, wherein the first cellular elements are white blood cells.

5. The method of claim 4, wherein the white blood cells include some white blood cells having surface epitopes which are selectively stained to be identifiable and separately enumerated from other white blood cells.

6. The method of claim 1, wherein the steps of examining, and enumerating utilize digital image analysis.

7. The method of claim 1, wherein all of the first and second cellular elements non-uniformly distributed within the sample are enumerated.

8. The method of claim 1, wherein the first thickness of the first cellular elements is greater than the second thickness of the second cellular elements.

9. The method of claim 1, wherein the second thickness of the second cellular elements relative to the height of the chamber is such that the second cellular elements distribute further distances within the chamber upon introduction of the sample into the chamber than the first cellular elements distribute.

10. The method of claim 1, wherein the chamber is height is equal to or less than twenty microns.

11. The method of claim 1, wherein the first elements are white blood cells and the second elements are red blood cells.

12. The method of claim 1, wherein the height of the chamber relative to the first thickness of the first cellular elements is such that substantially all of the first cellular elements are slightly compressed between the first and second planar members.

13. The method of claim 1, wherein the chamber height is such that the sample is drawn into the chamber by capillary action upon being introduced into the chamber.

14. The method of claim 1, wherein the height of the chamber relative to the first thickness of the first cellular elements is such that the first cellular elements tend to become entrapped within the chamber and are concentrated near an inlet of the chamber as the sample is drawn into the chamber.

15. A method for enumerating biologic particulates within an anticoagulated whole blood sample, comprising the steps of:

providing a chamber formed between a first planar member that is transparent and a second planar member, which members are separated from one another by a substantially uniform height, and which chamber has a known volume;

introducing an amount of sample into the chamber sufficient for the sample to extend between the first and second members for substantially the entire extent of the chamber, which sample includes biologic particulates having a thickness;

selecting the chamber height relative to the thickness of the biologic particulates within the sample such that the particulates non-uniformly distribute within the chamber upon introduction into the chamber;

examining substantially all of the sample within the chamber in an unlysed state and enumerating all of at least one of the particulates non-uniformly distributed within the chamber; and

determining a number per unit volume of the sample of the enumerated at least one of the particulates.

16. The method of claim 15 wherein the at least one biologic particulates enumerated includes platelets.