Page 1407 - Veterinary Immunology, 10th Edition

microwells before testing (Fig. 42.8). The serum to be tested is
VetBooks.ir added, followed, after washing, by labeled antigen. Any serum

antibodies present will bind the labeled antigen to the microwell
where it can be measured.

FIG. 42.8 The labeled antigen ELISA. The serum under test is
added to an antigen-coated plate. Bound antibodies are then
detected by an enzyme-labeled antigen.

A competitive ELISA can be used to measure hapten molecules
or viral antigens (Fig. 42.9). In this technique, each microwell is
coated with specific antibody before testing. In a single reaction, the

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