DSP (dithiobis(succinimidyl propionate)), Lomant's Reagent (Thermo Scientific™)

Thermo Scientific Pierce DSP (Lomant's Reagent) is a water-insoluble, homo-bifunctional N-hydroxysuccimide ester (NHS ester) crosslinker that is thiol-cleavable, primary amine-reactive, and useful for many applications. DSP contains an amine-reactive 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 and releasing N-hydroxy-succinimide. 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. DSP is non-sulfonated and insoluble in water, so it must first be dissolved in an organic solvent and then added to the aqueous reaction mixture. Because DSP does not possess a charged group, it is lipophilic and membrane-permeable and so useful for intracellular and intramembrane conjugation. A sulfonated analog of DSP (DTTSP) is water soluble. DSS, the non-cleavable analog of the DSP crosslinker is also available for applications that require a stable spacer arm that cannot be cleaved in the presence of reducing agents.

Thermo Scientific No-Weigh products are specialty reagents provided in a pre-aliquoted format. The pre-weighed packaging prevents the loss of reagent reactivity and contamination over time by eliminating the repetitive opening and closing of the vial. The format enables use of a fresh vial of reagent each time, eliminating the hassle of weighing small amounts of reagents and reducing concerns over reagent stability.

DSP 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-hydroxy-succinimide 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, the non-cleavable analog of DSP crosslinker is also available for applications that require a stable spacer arm that cannot be cleaved in the presence of reducing agents.

Features of Lomant's Reagent:

• Reactive groups: NHS ester (both ends)
• Reactive towards: amino groups (primary amines)
• Amine-reactive NHS ester reacts rapidly with any primary amine-containing molecule
• Disulfide bond in the spacer arm is readily cleaved by 10-50 mM DTT or TCEP at pH 8.5
• Spacer arm also cleavable with reducing SDS-PAGE sample loading buffer
• Cleavable crosslinker allows separation of crosslinked products
• Water-insoluble (dissolve first in DMF or DMSO); compare to DTSSP (Sulfo-DSP)
• Membrane-permeable, allowing for intracellular crosslinking

Applications:
• Chemical crosslinking of intracellular proteins prior to cell lysis and immunoprecipitation
• 'Fix' protein interactions to allow identification of weak or transient protein interactions
• Fix tissues for immunostaining without damaging RNA
• Protein crosslinking to create bioconjugates via single-step reactions
• Immobilize proteins onto amine-coated surfaces

Properties of DSP
• Alternative names: Lomant's reagent, DTSP
• Molecular formula: C₁₄H₁₆N₂O₈S₂
• Molecular weight: 404.42
• Spacer arm length: 12.0 Å (8 atoms)
• CAS number: 57757-57-0
• Reactive groups: NHS esters, react with primary amines at pH 7.0–9.0

DSP Specifications:
We manufacture DSP to the highest specifications to produce the most specific bioconjugates, ensure the integrity of your data and to provide you with the highest degree of consistency. Each lot of DSP is tested to meet the following minimum specifications.
• Identity: IR scan shows only peaks characteristic of the structure and functional groups of DSP
• Purity: > 95% by quantitative NMR (the highest standard for crosslinker purity)

Product References
Crosslinker Application Guide -- search for recent literature references for this product