Patent ID: 7422869

Claim:
A method for diagnosing the presence in an animal of an infection caused by a microorganism comprising obtaining a test sample from the animal, exposing the test sample to a population of the microorganism for a time sufficient to permit an antibody in the test sample that binds to an antibody binding site of the microorganism to bind to the antibody binding site, then putting the microorganisms that were exposed to the test sample in suspension, exposing the test sample and the population of the microorganisms to a labeled anti-antibody before, during, or after the microorganisms that were exposed to the test sample are put in suspension, determining a quantitative level of binding of the suspended microorganisms to antibodies in the test sample by detecting an absolute level of the label that is bound to the microorganisms, and comparing the level of the antibody binding in the test sample with the level of antibody binding from a negative control, wherein the presence of infection is diagnosed if the level of antibody binding in the test sample is higher than that in the control.