DSP crosslinker (DTSP; Dithiobis[succinimidyl propionate]; Lomant's Reagent) is a homobifunctional and cleavable crosslinker that is cell membrane permeable. DSP crosslinker has amine-reactive N-hydroxysuccinimide (NHS) esters at both ends of a cleavable, 8-atom (12.0 angstrom) spacer arm, and DSP cross links occur via these NHS esters. DSP crosslinking reagent contains a reducible disulfide (thiol) bond in the spacer arm that make it a good choice for various applications. The disulfide bond may be reduced with TCEP-HCl or DTT to reverse the crosslinked proteins.

A deuterated analog of DSP is available for mass spec studies. Use "light" DSP-d0 non-deuterated protein crosslinking reagent in combination with the "heavy", deuterated analog (DSP-d8) for mass spec experiments.

DSP crosslinker must be dissolved in an organic solvent, such as DMSO or DMF, then added to an aqueous crosslinking reaction. DSP is soluble in DMF, DMSO, acetone, and chloroform (up to 50mg/ml). DSP crosslinking reagent can be used to crosslink intracellular proteins and is often used for crosslinking in immunoprecipitation (IP), Co-IP and ChIP assays. If extracellular crosslinking is desired, then DTSSP crosslinker, the water soluble analog of DSP can be used.

Some precipitation of DSP crosslinking reagent can occur when diluting DMSO-dissolved DSP crosslinker in PBS. In order to minimize DSP precipitation when DMSO-dissolved DSP stock is added to PBS, gentle vortexing the PBS solution while dropwise adding the DMSO stock solution may help. Gentle warming of the reaction solution may also help minimize precipitation. If a precipitate is observed, then the protein and DSP crosslinker concentrations should be decreased. Alternatively, DMSO concentration may be increased up to 20% of the final concentration in the reaction solution.


Molecular Weight: 404.42

Spacer Length: 12.0 Å

CAS Number: 57757-57-0

Alternative names: 3,3'-Dithiodipropionic acid di(N-hydroxysuccinimide ester); Di(N-succinimidyl) 3,3′-dithiodipropionate; Dithiobis-succinimidyl propionate; Dithio-bis-succinimidyl propionate; Dithiobis(succinimidyl propionate); Lomant's Reagent; DSP cross-linker; DTSP crosslinker; DSP-d0