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MAL-dPEG®₄-(m-dPEG®₄)₃ (QBD-10416)



MAL-dPEG®4-(m-dPEG®4)3, product number QBD-10416, is a sulfhydryl-reactive, branched polyethylene glycol (PEG) product built around a tris core that is designed to modify surfaces and biomolecules containing free thiols. Vector Laboratories, Inc. manufactures this monodispersed PEG product with a single molecular weight and discrete chain length and sells it under the dPEG® tradename. MAL-dPEG®4-(m-dPEG®4)3 increases the hydrophilicity of conjugated molecules; reduces non-specific, hydrophobic interactions; and decreases or eliminates the antigenicity of conjugates. Also, because it is a single molecule, the analysis of conjugates made with MAL-dPEG®4-(m-dPEG®4)3 is simplified compared to the analysis of conjugates prepared with traditional dispersed PEG products. The maleimide reactive group reacts rapidly and selectively with free thiols (i.e., sulfhydryl groups) in aqueous media at pH 6.5 – 7.5. The maleimide-thiol reaction is a type of “click chemistry.” However, above pH 7.5, maleimide groups react with free amines in addition to free thiols.


Unit Size100 mg, 1000 mg
Molecular Weight1303.49; single compound
Chemical formulaC₅₈H₁₀₆N₆O₂₆
Purity> 96%
SpacersdPEG® Spacer is 43 atoms and 47.9 Å, Avg
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, DMAC, DMSO or water
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.


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). Chapter 1, p. 30.

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.

Applicable patents and legal notices are available at legal notices.

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