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dPEG®₂₄-SATA (S-acetyl-dPEG®₂₄-NHS ester) (QBD-10188)


dPEG®24-SATA, product number QBD-10184, is a hydrophilic, water-soluble version of the highly popular thiolation and crosslinking reagent known as SATA. Using straightforward, easy reactions, this reagent can be used to thiolate or crosslink biomolecules.


dPEG®24-SATA, also known as S-acetyl-dPEG®24-NHS ester, product number QBD-10188, is one of Quanta BioDesign’s versions of the widely popular thiolation reagent N-succinimidyl-S-acetylthioacetate (SATA). The acetyl-protected thiol is separated from the N-hydroxysuccinimidyl (NHS) ester by an amphiphilic, discrete polyethylene glycol (dPEG®) spacer. The long, flexible dPEG®24 spacer adds water solubility to the product.

Thiolation is the process of adding a sulfhydryl group to a molecule. Bioconjugation frequently employs thiolation because the reactions to install thiol groups on molecules or to react molecules with sulfhydryl groups are simple and often chemoselective.

The widely popular SATA reagent thiolates molecules with available amines via the NHS ester. Removal of the acetyl protecting group from the sulfhydryl permits crosslinking between the SATA-modified compound and a target molecule of interest that contains a thiol-reactive group, such as maleimide. Unfortunately, SATA is hydrophobic. Consequently, before use, SATA must be dissolved in a dry, water-miscible organic solvent.

Vector Laboratories’ dPEG®24-SATA inserts a single molecular weight spacer between the protected thiol and the NHS ester. The dPEG® spacer imparts water solubility to the molecule, allowing dPEG®24-SATA to dissolve and react in water without the need for an organic solvent. Also, the dPEG®24 spacer adds hydrodynamic volume to the molecule to which it is conjugated, reducing aggregation and precipitation of proteins conjugated to dPEG®24-SATA.

Hydroxylamine hydrochloride (CAS number 5470-11-1) easily removes the acetyl protecting group, exposing the sulfhydryl moiety for further reactions, for example, crosslinking to thiols or thiol-reactive groups like maleimides, bromoacetamides, and so forth. Any application that can be carried out with a traditional, non-PEGylated SATA reagent can be carried out with our SATA containing a dPEG® spacer.


Unit Size100 mg, 1000 mg
Molecular Weight1302.51; single compound
Chemical formulaC₅₇H₁₀₇NO₂₉S
Purity> 97%
SpacersdPEG® Spacer is 76 atoms and 89.1 Å
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, Acetontrile, DMAC or DMSO.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.


  1. Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). References to SATA which can be directly applied to the dPEG® pegylation versions: a) general description and use, p 71; b) modification of antibodies, pp 759; c)modification of amines on nucleus and DNA probes, p. 984 and d) modification of enzymes, avidin and streptavidin with pp. 90, 909 and 919.
  2. Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.
  3. Silica-Shelled Single Quantum Dot Micelles as Imaging Probes with Dual or Multimodality. Rumiana Bakalova, Zhivko Zhelev, Ichio Aoki, Hideki Ohba, Yusuke Imai, and Iwao Kanno. Anal. Chem. 2006, 78 (16) pp 5925–5932. July 14, 2006. DOI: 10.1021/ac060412b

Applicable patents and legal notices are available at legal notices.

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