Fmoc-Lys (biotin-PEG4)-OH is a Lysine embedded biotin PEG linkers containing a carboxylic group and Fmoc-protected amine. Reaction of carboxylic with primary amino (-NH2) forms stable, irreversible amide bonds. The Fmoc group can be deprotected under basic condition to release the free amine which can be used for further conjugations.
