SPDP-dPEG®₁₂-NHS ester

SPDP-dPEG®12-NHS ester, product number 10378, is Quanta BioDesign's water-soluble version of the immensely popular SPDP crosslinker. SPDP-dPEG®12-NHS ester is a heterobifunctional crosslinker. The N-hydroxysuccinimidyl (NHS) ester end of the molecule reacts with free amines. The opposite end is a 3-(2-pyridyldithio)-propionate functional group that reacts with sulfhydryl groups in thiol-containing molecules to form disulfide bonds. Between the two functional groups is an amphiphilic, single molecular weight, discrete polyethylene glycol (dPEG®) spacer.

The dPEG® Difference in Crosslinkers
Among the most popular heterobifunctional crosslinking reagents used in bioconjugate chemistry are those compounds that conjugate molecules containing free amine groups with molecules that contain sulfhydryl groups. The crosslinking product N-succinimidyl 3-(2-pyridyldithio)-propionate, known commonly by the acronym SPDP, is one of the most popular versions of this type of crosslinker. Unfortunately, SPDP and its popular varieties (LC-SPDP and Sulfo-LC-SPDP) are hydrophobic molecules. When conjugated to biomolecules, care must be taken not to modify the target molecules too much, because this can precipitate the conjugate products.

Ouramphiphilic dPEG® products create water-soluble conjugates. Our dPEG® products have all the benefits of traditional PEG products (including water solubility, increased hydrodynamic volume, and non-immunogenicity) without the liability of dispersity, which creates difficulties in analyzing the reaction products.

Using SPDP-dPEG®12-NHS ester in Bioconjugation Reactions
SPDP-dPEG®12-NHS ester, product number 10378, is used like SPDP and related hydrophobic products. However, precautions against overly modifying the target molecule are not necessary. The water-soluble dPEG® product does not cause the compounds to which it is conjugated to precipitate due to excessive hydrophobicity. The long spacer arm may facilitate the reaction of the SPDP end of the molecule with buried thiol groups.

Greg Hermanson's Bioconjugate Techniques, 3rd edition, describes SPDP and related products (Chapter 6) and describes Quanta BioDesign's dPEG® versions of these products (Chapter 18). Each of the chapters describing these crosslinkers contains detailed protocols for using them. Quanta BioDesign highly recommends and sells this book.

Bulk Quantities of SPDP-dPEG®12-NHS ester Are Available
If you need bulk product in a larger package size than our standard sizes, please contact us for a quote. Our commercial capabilities permit us to manufacture this product at any scale that you need.

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