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m-dPEG®₁₂-MAL (QBD-10289)



m-dPEG®12-MAL, product number QBD-10289, is a sulfhydryl-reactive, single molecular weight, with a discrete chain length PEG (dPEG®). This product modifies surfaces and biomolecules with free thiol groups through the maleimide reactive group. The non-immunogenic, methyl-terminated dPEG® chain has no charge but adds water solubility and hydrodynamic volume to molecules to which it is conjugated.

The reaction of the maleimide end of m-dPEG®12-MAL, product number QBD-10289, with a sulfhydryl proceeds best at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which creates confusing results. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

Published uses for m-dPEG®12-MAL include probing the molecular structure and function of proteins and coating nanoparticle surfaces. In particular, studies of molecular structure and function of proteins would not be possible with traditional, dispersed PEG products because the dispersed PEGs would have created an indecipherable mixture of conjugation products. Only a dPEG® product could work in this application.


Unit Size100 mg, 1000 mg
Molecular Weight710.81; single compound
Chemical formulaC₃₂H₅₈N₂O₁₅
Purity> 98%
SpacersdPEG® Spacer is 44 atoms and 50.7 Å
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, Acetonitrile, 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.


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). See all of the extensive references to the reactions of maleimides with a variety of compounds and applications, Hermanson, p.1174 (index for maleimides) and references therein.

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.

Homodimerisation of the Lymph Vessel Endothelial Receptor LYVE-1 through a Redox-Labile Disulfide is Critical for Hyaluronan Binding in Lymphatic Endothelium. Suneale Banerji, William Lawrance, Clive Metcalfe, David C. Briggs, Akira Yamauchi, Omer Dushek, P. Anton van der Merwe, Anthony J. Day, and David G. Jackson. The Journal of Biological Chemistry. 2016, October 12, 2016. DOI: 10.1074/jbc.M116.736926.

Interleukin-2 signalling is modulated by a labile disulfide bond in the CD132 chain of its receptor. Clive Metcalfe, Peter Cresswell and A. Neil Barclay. Open Biology. 2012, 2 (1). January 11, 2012. DOI: 10.1098/rsob.110036.

DksA2, a zinc-independent structural analog of the transcription factor DksA. Ran Furman, Tapan Biswas, Eric M. Danhart, Mark P. Foster, Oleg V. Tsodikov, Irina Artsimovitch. FEBS Letters. 2013, 587 (6) pp 614–619. January 31, 2013. DOI: 10.1016/j.febslet.2013.01.073.

Rapid ratiometric biomarker detection with topically applied SERS nanoparticles. Yu “Winston” Wang, Altaz Khan, Madhura Som, Danni Wang, Ye Chen, Steven Y. Leigh, Daphne Meza, Patrick Z. McVeigh, Brian C. Wilson and Jonathan T.C. Liu. Technology. 2014, 2 (2) pp 1-15. May 19, 2014. DOI: 10.1142/S2339547814500125.

Redox-regulated dynamic interplay between Cox19 and the copper-binding protein Cox11 in the intermembrane space of mitochondria facilitates biogenesis of cytochrome c oxidase. Manuela Bode, Michael W. Woellhaf, Maria Bohnert, Martin van der Laan, Frederik Sommer, Martin Jung, Richard Zimmermann, Michael Schroda, Johannes M. Herrmann. Molecular Biology of the Cell. April 29, 2015. DOI: 10.1091/mbc.E14-11-1526

A glutaredoxin in the mitochondrial intermembrane space has stage-specific functions in the thermo-tolerance and proliferation of African trypanosomes. Samantha Ebersoll, Blessing Musunda, Torsten Schmenger, Natalie Dirdjaja, Marian Bonilla, Bruno Manta, Kathrin Ulrich, Marcelo A. Comini, and R. Luise Krauth-Siegel. Redox Biology. 2018, 15, pp 532-547. January 31, 2018. DOI: 10.1016/j.redox.2018.01.011.

Applicable patents and legal notices are available at legal notices.

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