A Test Used to Identify Antibodies Against Treponema Pallidum in a Patient's

Question

A test used to identify antibodies against Treponema pallidum in a patient's serum is the
A)direct fluorescent-antibody test.
B)indirect fluorescent-antibody test.
C)direct agglutination test.
D)direct ELISA test.
E)neutralization test.

Accepted Answer

The indirect fluorescent-antibody test is commonly used to detect antibodies against Treponema pallidum, the bacteria that causes syphilis. In this test, patient serum is first exposed to a known antigen, followed by a fluorescently-tagged secondary antibody that will bind to any IgG antibodies present in the serum. If there are antibodies in the serum that recognize the Treponema pallidum antigen, they will bind to the antigen, which will then be detected by the secondary antibody. This secondary antibody will also bind to any antibodies present, allowing for visualization of the positive reaction by fluorescence microscopy.