Amplification of the biotin-avidin immunmofluorescence technique

An amplification of the immunofluorescence technique which uses biotinylated antibody and fluoresceinated avidin is described. By introducing a sandwich technique using fluorescein-conjugated goat anti-avidin, a 5-fold enhancement of staining over the conventional immunofluorescence method is achieved, and the brightness is more than twice that achieved with the simple biotin-fluoresceinated avidin reaction.