Description_x000D_ Features and Benefits_x000D_ Biotin-dPEG®23-amine is a single molecular weight dPEG® containing a terminal primary amine that permit biotin labeling with precise spacing to molecules containing a free carboxylic acid or aldehyde group. For small peptides and small molecules, the labeling can be site specific, while for larger molecules such as proteins, the labeling may be more random. The single molecular weight nature of the dPEG® spacer (87 Å) allows the user to precisely tailor the distance between the biotin and the target molecule in order to receive optimal binding between biotin and avidin._x000D_ Legal Information_x000D_ Products Protected under U.S. Patents # 7,888,536 B2_x000D_ dPEG is a registered trademark of Quanta BioDesign