Fluorescein Isothiocyanate (FITC) is a fluorescein-derived fluorophore which absorbs blue light (excitation maximum ~498 nm) and emits a characteristic green light (emission maximum ~ 519 nm). Known for their high quantum yield, high absorptivity, and conjugation efficiency, FITC fluorescence reagents represent a popular and cost-effective choice when labelling and visualising cellular targets. The bright, stable signal emitted by FITC-conjugated secondary antibodies is utilised in a range of biochemical applications, including: Western Blotting (WB), Immunofluorescence (IF), Immunohistochemistry (IHC), Immunocytochemistry (ICC), Flow Cytometry, ELISA, and Fluorescence Resonance Energy Transfer. Despite its relatively broad emission spectrum, FITC is compatible with a host of other fluorophores for use in multiplexing – an experimental setup whereby multiple targets can be detected simultaneously. Careful fluorophore selection is paramount when designing multiplex experiments to avoid emission spectral overlap. Examples of fluorophores commonly used alongside FITC include TRITC, Cyanine 3, Texas Red and Cyanine 5. Explore our portfolio of full length and fragmented FITC-conjugated secondary antibodies below, that are raised against a variety of primary antibody host species and their isotypes. Many of our antibodies are also available cross-adsorbed to limit cross-species reactivity and increase specificity of detection. Note: Researchers performing long duration imaging experiments or microscopic analyses involving high exposure times should consider Cyanine 5.5 labeled secondary antibodies. Cyanine 5.5 is a fluorophore with excellent photostability and therefore greater resistance to rapid photobleaching compared with FITC.