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m-dPEG®₂₅-DSPE (QBD-11373)



m-dPEG®25-DSPE, product number QBD-11373, modifies the lipid 1,2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) with a long (77 atoms, 90.0 Å), methoxy-terminated, single molecular weight, discrete polyethylene glycol (dPEG®) spacer. This product is designed to protect liposomes and micelles from opsonization and elimination by the reticuloendothelial system (RES). The m-dPEG®25 spacer offers protection from opsonization comparable to the traditional polymer mPEG2000, while the smaller spacer size compared to mPEG2000 allows for more efficient uptake into cells. The methyl-capped dPEG® spacer has a neutral charge.

Vector Laboratories’ dPEG® products are highly pure single molecular weight compounds with a discrete chain length. Traditional PEG compounds used to coat liposomes and micelles consist of an intractable mixture of different chain lengths and molecular weights. The non-uniform polymeric mixture leads to irreproducible purity profiles, unlike dPEG® compounds.


Unit Size25 mg, 100 mg
Molecular Weight1891.416; single compound
Chemical formulaC₉₃H₁₈₄NO₃₄P
Purity> 98%
SpacersdPEG® Spacer is 77 atoms and 90.0 Å
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, Chloroform, or Acetonitrile.
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). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

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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