Vector Laboratories fluorochrome-conjugated streptavidin and avidin reagents are highly purified and possess very low non-specific binding properties. They have extremely high affinity for biotin. These fluorescent conjugates can be used to detect biotinylated secondary antibodies and other macromolecules in applications such as immunofluorescence, in situ hybridization, or flow cytometry. Amplification of fluorescent signals can be easily achieved with our biotinylated secondary antibodies followed by our highly purified fluorochrome-labeled streptavidin or avidin. Using a biotin/avidin or biotin/streptavidin detection system results in an additional layer of amplification over a directly conjugated secondary antibody.