fluorescent antibody technique
n.
Either of two techniques used to test for antigen with a fluorescent antibody: direct, in which immunoglobulin conjugated with a fluorescent dye is added to tissue and combines with a specific antigen; or indirect, in which unlabeled immunoglobulin is added to tissue and combines with a specific antigen, after which the antigen-antibody complex may be labeled with a fluorescent antibody.