A secondary antibody specifically binds to a primary antibody but ideally not to any antigen that is present in the specimen to be analyzed. Usually secondary antibodies are conjugated to an enzyme, a fluorophore or other labels that allow detection of the primary-secondary antibody complex.
Species specific secondary antibodies have a strong preference for primary antibodies originating from one species. This allows multiplex staining in which several primary antibodies from different host species are combined in one experiment.
NanoTags unique FluoTags are ideal for time saving multiplexing experiments with high precision. Since Nanobodies are monovalent, they can be directly incubated with primary antibodies without forming non-functional clusters.