EGS is a homobifunctional amine-specific crosslinking reagent based on NHS-ester reactive groups for selective conjugation of primary amines.EGS contains two NHS ester groups at both ends of a 12-atom spacer that readily react towards primary amines at pH 7-9.EGS is not water soluble and must be dissolved in an organic solvent such as DMSO or DMF prior to use.EGS is membrane permeable and can be used for intracelular crosslinking.The crosslink formed when using EGS can be cleaved by treatment with hydroxylamine at 35 °C at pH 8.5.