DTSP, also known as Lomant’s reagent is a homobifunctional amine-specific crosslinking reagent based on NHS-ester reactive groups for selective conjugation of primary amines.DTSP contains two NHS ester groups at both ends of a 8-atom spacer that contains a cleavable disulfide bond.The NHS ester groups readily react towards primary amines at pH 7-9.DTSP is not water soluble and must be dissolved in an organic solvent such as DMSO or DMF prior to use.DTSP is membrane permeable and can be used for intracelular crosslinking.The disulfide bond can be readily cleaved by treatment with DTT or TCEP.