For detection of small amounts of a given antigen or antibody in test sample, the "capture" assay is used. In this case, an unlabeled antibody to a given molecule is laid down on the plate to "capture" the small amount of antigen or antibody present in the test sample. The second antibody to this antigen or antibody is labelled with the appropriate fluorochrome, and the rest of the tests proceed as in the direct assay described previously. While the radioassays remains the "gold" standard for many clinical laboratories, more research and clinical laboratories are turning to the ELISA since it does not present the problem of radioactivity hazards or, perhaps more important, the removal of radioactive wastes (mainly a problem of disposal sites).
No comments:
Post a Comment