Screening arrangement for screening immunoassay tests and agglutination tests

• US 7,803,633 B2
• Filed: 04/30/2008
• Issued: 09/28/2010
• Est. Priority Date: 07/14/1998
• Status: Expired due to Fees

• Current Assignee: Cozart Bioscience Limited (Abbott Laboratories)
• Original Assignee: Cozart Bioscience Limited (Abbott Laboratories)
• Inventors: Hand, Christopher William, Jones, Osborn Pierce, Spivey, Robin James, Baldwin, Dene
• Primary Examiner(s): Shibuya; Mark L
• Assistant Examiner(s): DIRAMIO, JACQUELINE A
• Application Number:
  US12/150,700
• Publication Number:
  US 20080287316A1
• Time in Patent Office: 881 Days
• Field of Search: 435/4, 435/7.1, 435/287.1, 435/287.2, 435/287.3, 436/501, 436/164, 436/172, 436/69, 436/805, 422/68.1, 356/318, 356/338, 356/343
• US Class Current: 436/164
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/81 Packaged device or kit
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 436/805 Optical property

Abstract

A screening device for performing an immunoassay test to detect the presence of a compound in a body fluid. The device includes a holder for removably receiving a membrane to which the fluid has been applied. Light is directed to the membrane. A photodetector measures the concentration of the light reflected back from the membrane. Specifically, the concentrations of reflected light from a control zone and a test zone are measured. Signals representative of the measured light concentrations are applied to a processor. If a specified concentration of predetermined light from a control zone on the membrane is detected, the processor considers the test to be successful. In the test is successful, the processor, based upon the measured concentration of reflected light from the test zone, generates data representative of the presence of the compound.

Claims

1. A method of conducting and screening an agglutination test to identify the presence of an analyte in a sample, said test producing agglutination areas and background areas, said method comprising the steps of:

mixing said sample with one or more agglutination reactants to form a sample and reactant mixture;

flowing said sample and reactant mixture through a channel where an agglutination reaction or an agglutination pre-processing reaction occurs;

receiving the mixture in a reaction chamber where the agglutination reaction occurs or is completed;

illuminating said reaction chamber;

detecting the intensity of light which is reflected from said agglutination areas and said background areas of said reaction chamber;

representing the intensity of said detected light in a digitized data array;

determining a threshold intensity by analyzing the distribution of pixel intensities across said data array to determine the intensity below or above which a pre-set percentage of pixels lie;

thresholding said data array using the threshold intensity to distinguish between said background areas and said agglutination areas;

identifying said agglutination areas;

estimating the number of said agglutination areas;

determining whether said agglutination areas exhibit a statistically significant result; and

outputting said results.

2. The method according to claim 1 further including the step of performing a noise reduction of said digitized data array prior to thresholding said digitized data.

3. The method according to claim 1, wherein

the step of detecting the intensity of the light is carried out by an array of photosensitive detectors;

the step of thresholding said data array is carried out in a threshold processor which is coupled to an output of a digitizer;

the step of identifying said agglutination areas is carried out in a first data processor which is coupled to said threshold processor; and

the step of determining whether said agglutination areas exhibit a statistically significant result is carried out in a second data processor which is coupled to an output of said first data processor.

4. The method according to claim 1, wherein the step of mixing said sample with said one or more agglutination reactants comprises the step of mixing said sample with an antibody to said analyte.

5. The method according to claim 1, wherein the step of mixing said sample with said one or more agglutination reactants comprises the step of mixing said sample with beads coated with said analyte or analyte component.

6. The method according to claim 5, wherein said analyte is a viral antibody and said analyte component is a viral antigen.

7. The method according to claim 1, wherein the step of mixing said sample with said one or more agglutination reactants comprises the step of mixing said sample with an antibody to said analyte and with beads coated with said analyte or analyte component.

8. The method according to claim 1, wherein the one or more agglutination reactants are held in an immobilized state in a sample flow path.

9. The method according to claim 1 further comprising the steps of separating said sample into a plurality of channels, each of the channels containing an agglutination reactant in an immobilized state;

flowing said sample through the channels to hydrate the immobilized reactants; and

receiving flows in respective reaction chambers.

10. The method according to claim 1, further comprising the step of hydrating said immobilized agglutination reactants with said sample as said sample flows along a flow path.