PC-Biotin-PEG4-PEG3-azide is useful for introducing a biotin moiety to alkyne-containing biomolecules using Click Chemistry. The extended hydrophilic spacer arm provides high solubility to the labeled molecules in aqueous media. Captured biomolecules can be efficiently photoreleased using near-UV, low intensity lamp (e.g. 365 nm lamp at 1-5 mW/cm2).
