FITC-Tag Antibodies

FITC is an isothiocyanate derivative of fluorescein whose reactive -N=C=S group attacks primary amine groups on a protein or antibody, forming a stable thiourea bond and leaving the fluorescein label covalently attached.¹ Once conjugated, FITC gives an absorbance maximum around 495 nm and an emission maximum around 520 nm, producing the yellow-green signal used across fluorescence microscopy and flow cytometry.²

Because FITC itself is not immunogenic on its own, dedicated anti-FITC antibodies are used to detect, amplify or capture FITC-conjugated proteins and antibodies in assays where a direct fluorescence readout is not sufficient or where a secondary signal amplification step is needed.