Thermo Scientific Pierce LC-SPDP is a long-chain crosslinker for amine-to-sulfhydryl conjugation via NHS-ester and pyridyldithiol reactive groups that form cleavable (reducible) disulfide bonds with cysteine sulfhydryls.

Features of LC-SPDP:

• Reactive groups: NHS ester and pyridyldithiol
• Reactive towards: amino and sulfhydryl groups
• Releases a detectable by-product when reacted with a free sulfhydryl group; by measuring the release of pyridine-2-thione at 343 nm, the reaction can be easily followed
• Disulfide bond in the spacer arm is readily cleaved by 10-50 mM DTT or TCEP at pH 8.5
• Spacer arm is also easily cleaved using reducing SDS-PAGE sample loading buffer
• Cleavable crosslinker allows separation of crosslinked products
• Water-insoluble (dissolve first in DMF or DMSO)
• SPDP crosslinker is membrane permeable, so crosslinking can be done inside the cells
• Compare to other varieties of SPDP-type reagents, including pegylated forms

Applications:
• Reversible crosslinking of proteins
• Adding sulfhydryl groups to proteins by attachment to lysine residues
• Protein crosslinking to create antibody-enzyme and other bioconjugates via a two-step reaction
• Attaching haptens to carrier proteins for antibody production
• Preparing immunotoxin conjugates

Specifications:
We manufacture LC-SPDP to the highest specification to produce the most specific bioconjugate, ensures the integrity of your data and to provide you with the highest degree of consistency. Each lot of LC-SPDP is tested to ensure it is >95% pure by quantitative NMR (the highest standard for crosslinker purity).

We offer three analogs of SPDP: the standard version (SPDP), a derivative with a longer spacer arm (LC-SPDP), and a sulfonated water-soluble variety (Sulfo-LC-SPDP). SPDP (N-Succinimidyl 3-(2-pyridyldithio)-propionate) and LC-SPDP (Succinimidyl 6-(3-[2-pyridyldithio]-propionamido)hexanoate) are heterobifunctional, thiol-cleavable and membrane permeable crosslinkers. They each contain an amine-reactive N-hydroxysuccinimide (NHS) ester that will react with lysine residues to form a stable amide bond. The other end of the spacer arm is terminated in the pyridyl disulfide group that will react with sulfhydryls to form a reversible disulfide bond.

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

Related Products
SPDP (succinimidyl 3-(2-pyridyldithio)propionate)
Pierce™ Premium Grade SPDP
Sulfo-LC-SPDP (sulfosuccinimidyl 6-(3'-(2-pyridyldithio)propionamido)hexanoate)