Radial immunodiffusion . Measures proteins in blood or urine. Bound antibodies form characteristic patterns that can be detected. Indirect immunofluorescence . Most frequently employed to detect antibodies.
Blood is placed on slides with antigens that bind with the antibody being tested.
Antibodies present in the blood show up as tiny dots of fluorescent light. Flow cytometry . Measures the levels of different lymphocytes in the blood. An antibody known to bind with a particular type of lymphocyte is added to the blood sample, and the amount of binding is recorded. Monoclonal antibodies .