FITC

Laser: Blue Diode/HeAr Laser
Excitation: 488 nm
Emission: 525 nm

FITC
(Fluorescein Isothiocyanate), a small organic molecule (389 Da), currently the most commonly-used fluorescent dye for FACS analysis. FITC is typically conjugated to proteins via primary amines (i.e., lysines). Usually in the range of 3 to 6 FITC molecules are conjugated to each antibody; higher conjugations can result in solubility problems and reduced brightness. FITC has a high efficiency of energy transfer, approximately half of the absorbed photons are emitted as fluorescent light.