BDP 650/665 is a bright, red-emitting fluorophore for Cyanine5 (Cy5) channel. The dye has a high molar extinction coefficient and a good emission quantum yield. The dye is moderately hydrophobic but can be used to label biomolecules in an aqueous environment, so it is a good alternative to Cy5.
Maleimide is a thiol-reactive group. The compound can be used for the labeling of cysteine residues of proteins and peptides, among other SH-containing molecules.