The capability of binding avidin or streptavidin via either biotin binding sites or through antigen binding sites, makes these biotinylated antibodies unique. These antibodies can be used either as part of preformed complexes or in sequence to amplify fluorescent signals. When used in sequence, the target is first labeled with fluorochrome-conjugated avidin or streptavidin, followed by incubation with Biotinylated Anti-Avidin or Biotinylated Anti-Streptavidin, followed by a second layer of fluorochrome-conjugated avidin or streptavidin. This sequence can be repeated. This multi-layered approach introduces more fluorochromes at the target site and can provide a multi-fold amplification over a single layer.