Chromophore allows for direct spectrophotometric quantitation of total incorporated biotin PEG4 linker preserves biotin/avidin affinity as well as increases solubility Aromatic succinimidyl ester allows for higher efficiency modification of amines in aqueous buffers Molecular Formula: C 38 H 50 N 8 O 1 0 S Packaging: Glass Bottle Recommended Storage 2° to 8°C