Fluorescent antibody technique
In medicine and immunohistochemistry, fluorescent antibody technique (immunofluorescence) is a immunologic test for "tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (fluorescent antibody technique, direct) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (fluorescent antibody technique, indirect). The tissue is then examined by fluorescence microscopy."
Direct fluorescent antibody technique
Fluorescent antibody techinique, also known as direct immunofluorescence, is a straightforward laboratory test to detect antigens using fluorescently labelled antigen-specific antibody. It has been widely used in detection of microorganisms.
Indirect fluorescent antibody technique
Indirect fluorescent antibody technique is "a form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody."