Method for obtaining increased particle concentration for optical examination

• US 6,867,049 B1
• Filed: 09/27/2000
• Issued: 03/15/2005
• Est. Priority Date: 09/27/2000
• Status: Expired due to Term

• Current Assignee: Becton, Dickinson & Co
• Original Assignee: Becton, Dickinson & Co
• Inventors: Scrivens, Brian G., Frank, Robert S., Berndt, Klaus W., Livingston, Dwight
• Primary Examiner(s): Cole, Monique T.
• Application Number:
  US09/670,739
• Time in Patent Office: 1,630 Days
• Field of Search: 436/177, 436/180, 422/68.1, 422/255, 422/58, 422/99, 422/228, 422/946, 422/947, 422/948, 422/100, 204/767, 137/544, 137/861, 137/883, 137/44
• US Class Current: 436/177
• CPC Class Codes: B01L 2300/0681 Filter
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 3/502723 characterised by venting arrangements
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 15/0272 with screening; with classification by filtering B01D takes precedence
• CPC Class Codes: G01N 15/0625 Optical scan of the deposits
• CPC Class Codes: G01N 2015/012 Red blood cells
• CPC Class Codes: G01N 2015/016 White blood cells
• CPC Class Codes: Y10T 137/0898 By shifting of liquid level
• CPC Class Codes: Y10T 137/794 With means for separating solid material from the fluid
• CPC Class Codes: Y10T 137/877 With flow control means for branched passages
• CPC Class Codes: Y10T 137/87877 Single inlet with multiple distinctly valved outlets
• 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

The present invention relates to a method and apparatus for analyzing a blood or other biological fluid sample in a quiescent state, whereby particulate constituents of biological samples that contain sparse populations of interesting cellular species can be enumerated and inspected using an optical scanning instrument. Specifically, this invention relates to a method and apparatus for obtaining increased cellular or particulate concentrations within the use of said optical scanning method.

Claims

1. A method for obtaining a liquid sample having an increased cellular or particulate concentration for optical examination comprising:

(a) providing an apparatus comprising;

a separation chamber;

a wall surrounding said separation chamber;

a sample entrance;

venting channels;

a separation wall in said separation chamber, dividing said chamber into two compartments, said separation wall having at least one separation channel, whereby said at least one separation channel has the appropriate size and dimensions to allow undesired cellular or particulate species to pass through, while excluding larger desired cellular or particulate species from passing through; and

a flow path in said separation chamber;

(b) depositing a liquid sample into the sample entrance of said apparatus;

(c) allowing the sample to flow into the separation chamber;

(d) allowing the sample to flow along the flow path in said separation chamber;

(e) allowing the sample to advance to the separation wall;

(f) allowing the sample to advance through the separation wall and the at least one separation channel;

(g) allowing the portion of the sample containing undesired cellular or particulate species to advance to the second compartment;

(h) allowing the sample to advance to the end of the separation chamber; and

(i) obtaining in the first compartment the sample having an increased cellular or particulate concentration, which has been prevented from passing through said separation channel(s).

2. The method according to claim 1 wherein said liquid sample is blood.

3. The method according to claim 1 wherein said apparatus further comprises a lid portion.

4. The method according to claim 3 wherein said lid portion has at least one opening for sample delivery.

5. The method according to claim 1 wherein said separation wall has at least one first separation channel and at least one second separation channel.

6. The method according to claim 5 wherein said separation channels are of different sizes.

7. The method according to claim 5 wherein said first separation channel is about 3 to 10 μ

m deep by 5 to 50 μ

m wide.

8. The method according to claim 5 wherein said second separation channel is about 0.5 to 1.5 μ

m deep by 50 to 1000 μ

m wide.

9. The method according to claim 1 wherein said apparatus further comprises a plurality of notches in said separation chamber.

10. The method according to claim 1 wherein said apparatus further comprises a plurality of notches in said first compartment of said separation chamber.

11. The method according to claim 1 wherein said apparatus further comprises a plurality of notches in said second compartment of said separation chamber.

12. The method according to claim 1 wherein said apparatus further comprises a plurality of notches in said first compartment and second compartment of said separation chamber.

13. The method according to claim 1 wherein said separation wall has a plurality of separation channels of the same size.

14. The method according to claim 1 wherein said separation wall has a plurality of separation channels of different sizes.

15. The method according to claim 9, further comprising allowing the sample to flow past each notch in the separation chamber.

16. The method according to claim 10 further comprising, after step (d), allowing the sample to flow past each notch in the first compartment.

17. The method according to claim 11 further comprising, after step (g), allowing the sample to flow past each notch in the second compartment.

18. The method according to claim 12 further comprising, after step (d), allowing the sample to flow past each notch in the first compartment;

and after step (g), allowing the sample to flow past each notch in the second compartment.