Increased sensitivity of the indirect immunofluorescence method by use of a tertiary fluorochrome-labeled antibody.

The standard protocol for indirect immunofluorescence was modified by the addition of a third layer of antibodies. These antibodies were conjugated with the same fluorochrome as the secondary antibodies. This modification resulted in significant enhancement of the sensitivity of immunolabeling. The method may be useful when the standard indirect immunofluorescent technique results in weak labeling, and also to regain labeling in sections where specific fluorescence has faded.