The Biotinylated Target Labeling Kit provides convenient means for the site-specific, purification-free labeling of small amounts of biotinylated molecules (e.g., proteins) with our fluorescent dye. This kit can be used for the labeling of any protein or peptide carrying one or multiple biotin-tags and contains material sufficient for labeling for 500 single-point spectral shift measurements. Labeling can be completed in 15 minutes; no removal of excess dye is required. The labeling dye binds efficiently to biotin-tags and shows fluorescence excitation and emission maxima at approximately 650 nm and 670 nm, respectively.