Method and apparatus for entry and storage of specimens into a microfluidic device

• US 20040265172A1
• Filed: 06/27/2003
• Published: 12/30/2004
• Est. Priority Date: 06/27/2003
• Status: Abandoned Application

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Inventors: Blankenstein, Gert, Peters, Ralf-Peter, Pugia, Michael J., Profitt, James A.
• Application Number:
  US10/608,671
• Publication Number:
  US 20040265172A1
• Time in Patent Office: Days
• US Class Current: 422/400
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/0684 Venting, avoiding backpressure, avoid gas bubbles
• CPC Class Codes: B01L 2300/0806 Standardised forms, e.g. compact disc [CD] format
• 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 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0478 pistons
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/5025 for parallel transport of multiple samples
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• 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: Y10T 436/2575 Volumetric liquid transfer

Abstract

A microfluidic device for analyzing biological samples is provided with a sample inlet section including an inlet port, a capillary passageway communicating with the inlet port and with an inlet chamber. The inlet chamber includes means for uniformly distributing the sample liquid across the inlet chamber and purging the air initially contained therein.

Claims

1. A microfluidic device for assaying a liquid biological sample of 20 μ

L or less comprising;

(a) an inlet port for receiving said sample;

(b) a capillary passageway in fluid communication with said inlet port;

(c) an inlet chamber in fluid communication with the capillary passageway of (b), thereby permitting said sample to flow into said inlet chamber, said inlet chamber containing means for uniformly distributing said sample across said chamber and, displacing air from said chamber; and

(d) at least one vent passageway for removing air displaced by said liquid sample.

2. A microfluidic device of claim 1 wherein said means for uniformly distributing said sample is at least one groove extending across said inlet chamber.

3. A microfluidic device of claim 1 wherein said means for uniformly distributing said sample is at least one weir extending across said inlet chamber.

4. A microfluidic device of claim 2 or 3 wherein said at least one groove or at least one weir contains wedge-shaped cutouts to facilitate uniform flow of said sample.

5. A microfluidic device of claim 1 wherein said means for uniformly distributing said sample is a microstructure comprising an array of posts disposed across said inlet chamber.

6. A microfluidic device of claim 5 wherein said posts contain wedge-shaped cutouts to facilitate uniform flow of said sample.

8. A microfluidic device of claim 1 further comprising an blood anti-coagulant deposited in said inlet chamber.

9. A microfluidic device of claim 1 further comprising an overflow chamber in fluid communication with said inlet chamber, said overflow chamber for receiving said sample in excess of the amount needed to fill said inlet chamber.

10. A microfluidic device of claim 9 wherein said overflow chamber contains an indicator to detect the presence of excess of said sample.

7. A microfluidic device of claim I wherein said inlet port is tapered to engage the corresponding shape of a pipette for depositing said sample

11. A method of supplying liquid to a microfluidic device having an inlet port in fluid communication with an inlet chamber via a capillary passageway, said method comprising.

(a) introducing a portion of said liquid into said inlet port;

(b) transferring by positive pressure or capillary forces said liquid portion of (a) to said inlet chamber via said capillary passageway;

(c) distributing said liquid portion of (a) uniformly across said inlet chamber and purging air from said chamber completely.

12. A method of claim 11 wherein excess of said sample is diverted to an overflow chamber after said inlet chamber is filled.

13. A method of claim 12 wherein the presence of said excess is detected by an indicator in said overflow chamber.