Immunoglobulin (IgG) from goat serum has been labelled with the fluorescein isothiocyanate dye to produce a green-emitting antibody with a high fluorophore-to-protein ratio. The resulting antibody can be used as a positive control for intracellular antibody delivery with OZ Biosciences’ Ab-DeliverIN reagent (cat. #AI21000). IgG-FITC is provided at a 100 µg/ml concentration in DPBS pH 7.4. FITC properties: *Absorption maximum: 492 nm *Emission maximum:520 nm *Extinction coefficient:75000 M-1cm-1 *Quantum yield:0.79