Method and apparatus for performing a lateral flow assay

• US 8,354,270 B2
• Filed: 10/08/2007
• Issued: 01/15/2013
• Est. Priority Date: 11/23/1998
• Status: Expired due to Fees

• Current Assignee: Relia Biotechnologies (Shenzhen) Ltd.
• Original Assignee: Relia Diagnostic Systems Inc.
• Inventors: Polito, Alan J., Thayer, Richard M., Dinello, Robert K., Sierra, George H., Nixon, Dennis, Phillips, Alan, Neubarth, Stuart
• Primary Examiner(s): Hines, Ja'Na
• Application Number:
  US11/868,923
• Publication Number:
  US 20080031779A1
• Time in Patent Office: 1,926 Days
• Field of Search: None
• US Class Current: 435/285.2
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: G01N 27/227 Sensors changing capacitance upon adsorption or absorption of fluid components, e.g. electrolyte-insulator-semiconductor sensors, MOS capacitors G01N27/225 takes precedence
• CPC Class Codes: G01N 33/4875 Details of handling test elements, e.g. dispensing or storage, not specific to a particular test method test-elements per se B01L, automatic analysers G01N35/00, in-vivo analysis on the human body for medical diagnosis A61B
• CPC Class Codes: G01N 33/54386 Analytical elements
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures
• CPC Class Codes: Y10T 436/114998 with treatment or replacement of aspirator element [e.g., cleaning, etc.]

Abstract

An embodiment of the present invention provides a-method for performing a lateral flow assay. The method includes depositing a sample on a test strip at an application region, detecting a first detection signal arising from the test strip in the first detection zone, and generating a baseline for the first measurement zone by interpolating between values of the detection signal outside of the first measurement zone and inside of the first detection zone. The method may include locating a beginning boundary and an ending boundary for the first measurement zone on the test strip. Additional detection zones having measurement zones may also be incorporated with the embodiment.

Claims

1. An apparatus for conducting a lateral flow assay on a test strip for detection of an analyte in a sample comprising:

a housing having a receptacle that retains the test strip;

an autostart means comprising (i) a capacitance sensor that senses a change in capacitance when a sample or buffer is applied to the test strip in the receptacle and initiates timing of the assay, and (ii) a means for regulating voltage across the capacitance sensor; and

a test strip comprising (i) a first analyte binding agent coupled to a detection agent, and (ii) a second analyte binding agent or an analyte non-specific agent coupled to a detection agent.

2. The apparatus of claim 1, wherein the test strip comprises:

a first measurement zone including a first agent immobilized therein which is capable of binding the first analyte binding agent, and

a second measurement zone including a second agent immobilized therein which is capable of binding the second analyte binding agent or the analyte non-specific agent.

3. The apparatus of claim 1, further comprising a detection means for detecting a signal from the test strip.

4. The apparatus of claim 1, further comprising a heating element positioned to lie under and contact the test strip.

5. The apparatus of claim 1, further comprising a first sensor that detects a signal emitted by the test strip.

6. The apparatus of claim 1, further comprising a processor, memory resources, and software for determining the amount of analyte in the sample.

7. The apparatus of claim 1, wherein the means for regulating voltage across the capacitance sensor changes the voltage across the capacitance sensor in a periodic pattern.

8. The apparatus of claim 1, wherein the means for regulating voltage across the capacitance sensor is a current source, and a switch.

9. The apparatus of claim 1, wherein the capacitance sensor is part of an inductor-capacitor (“

LC”

) circuit.

10. The apparatus of claim 3, wherein the detection means detects a reflectance, fluorescence or radiation signal.

11. The apparatus of claim 4, further comprising a temperature feedback control.

12. The apparatus of claim 5, wherein the first sensor is an optical sensor.

13. The apparatus of claim 5, wherein the receptacle retains a cartridge containing the test strip, wherein the apparatus further comprises a second sensor that detects a code on the cartridge, and wherein the second sensor is an optical sensor.

14. The apparatus of claim 13, further comprising a detector that detects insertion of the cartridge containing the test strip into the receptacle.

15. The apparatus of claim 14, wherein the detector is an infrared sensor.

16. The apparatus of claim 1, further comprising:

a heating element for locally heating the test strip;

a sensor that detects a signal emitted by the test strip; and

a processor, memory resources, and software for determining the amount of analyte in the sample.