The FIT-22 antibody reacts with both fluorescein isothiocyanate (FITC) alone and FITC conjugated with antibody or streptavidin. When FIT-22 antibody is used in a three-step staining procedure or separation of FITC-antibody labeled cells, it does not quench FITC fluorescence or react with tested mouse and human cells. The FIT-22 antibody can be used for separation of FITC-antibody labeled cells or as a secondary step to amplify FITC conjugated primary antibody signals (i.e. biotinylated FIT-22 as secondary step, followed by Streptavidin-FITC).