Thermo Scientific Pierce DSS, also called disuccinimidyl suberate, is noncleavable and membrane permeable crosslinker that contains an amine-reactive N-hydroxysuccinimide (NHS) ester at each end of an 8-carbon spacer arm.
NHS esters react with primary amines at pH 7-9 to form stable amide bonds, along with release of the N-hydroxysuccinimide leaving group. Proteins, including antibodies, generally have several primary amines in the side chain of lysine (K) residues and the N-terminus of each polypeptide that are available as targets for NHS-ester crosslinking reagents. DSS is first dissolved in an organic solvent such as DMF or DMSO, then added to the aqueous crosslinking reaction. BS3, the water soluble analog of DSS is also available for applications that require a hydrophilic crosslinker (e.g. to effect cell-surface crosslinking). DSS and BS3 have essentially identical crosslinking activity toward primary amines.