Metering technique for lateral flow assay devices

• US 8,173,380 B2
• Filed: 08/31/2010
• Issued: 05/08/2012
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Yang, Kaiyuan, Wei, Ning, Feaster, Shawn Ray
• Primary Examiner(s): Cook, Lisa
• Application Number:
  US12/872,225
• Publication Number:
  US 20100323392A1
• Time in Patent Office: 616 Days
• Field of Search: None
• US Class Current: 435/7.21
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387

Abstract

A diagnostic test kit for detecting an analyte residing in a test sample is provided. The kit employs a lateral flow device that contains a membrane. A metering channel is formed in the membrane that is capable of delivering a controlled volume of the test sample to a detection zone upon initiation of the assay. Such a metering channel is particularly effective for embodiments in which the test sample has a relatively low volume, such as less than about 100 microliters, in some embodiments from about 0.5 to about 25 microliters, and in some embodiments, from about 1 to about 10 microliters. For example, whole blood drops obtained from patients with a lancet typically have a volume of less than about 3 microliters. Despite their low volume, the present inventors have discovered that the blood drops may still be accurately analyzed for the presence of an analyte using lateral flow detection techniques.

Claims

1. A method for performing a lateral flow assay, the method comprising:

contacting a test sample having a volume of less than about 100 microliters with a metering channel that is formed in a membrane;

placing a bridging member over the metering channel and in fluid communication with the membrane; and

supplying a diluent to the membrane to facilitate flow of the test sample to a detection zone.

2. The method of claim 1, wherein the test sample is whole blood.

3. The method of claim 2, further comprising separating plasma, serum, or both from the whole blood for analysis.

4. The method of claim 1, wherein the volume of the test sample is less than about 25 microliters.

5. The method of claim 1, wherein the volume of the test sample is less than about 10 microliters.

6. The method of claim 1, wherein the metering channel is formed by laminating separate portions of a membrane onto a support so that the metering channel is formed therebetween.

7. The method of claim 1, wherein the metering channel is formed using a microfabrication technique.

8. The method of claim 7, wherein the microfabrication technique includes laser ablation.

9. The method of claim 7, wherein the microfabrication technique includes applying a solvent treatment to the membrane.

10. The method of claim 1, wherein the metering channel has a width that is the same or substantially equal to the width of the membrane.

11. The method of claim 1, wherein length of the metering channel is from about 0.01 to about 4 millimeters.

12. The method of claim 1, wherein the membrane is laminated to a support, the support defining a bottom surface of the metering channel.

13. The method of claim 1, further comprising treating at least a portion of the metering channel with a wetting agent, an agglutinating agent, or combinations thereof.

14. The method of claim 1, wherein the bridging member also functions as a blood separation filter.

15. The method of claim 1, further comprising disposing an absorbent member within the metering channel.

16. The method of claim 1, wherein the detection zone is defined by the membrane.