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Amino-dPEG®₁₂-Tris(-dPEG®₂₄-t-butyl ester)₃ (QBD-11449)



Amino-dPEG®12-Tris(dPEG®24-t-butyl ester)3, product number QBD-11449, is a branched, four-arm, single molecular weight, discrete-length polyethylene glycol (dPEG®) product. Built around a tris core, the product consists of a carboxylate-reactive, medium-length (40 atoms) amino-dPEG®12 tail joined to one side of the tris core and three, equally long (76 atoms) tert-butyl-ester-protected dPEG®24 branches. The total length from the terminal, carboxylate-reactive amine tail to the carbonyl carbons on the branches is 126 atoms (102.8 Å, average).

Amino-dPEG®12-Tris(dPEG®24-t-butyl ester)3 increases the hydrodynamic volume and water solubility of conjugates made with it. The increased hydrodynamic volume protects conjugates from renal clearance and can shield them from the immune system.

The tert-butyl-ester-protected dPEG®24 branches can be deprotected with trifluoroacetic or formic acid. Once deprotected, the free carboxylic acids can be used for charge modification of the conjugate molecule or further functionalized for additional reactions. In addition to conjugate charge modification, potential uses for this product include PK/BD optimization of biomolecules, surface coating and passivation to prevent non-specific interactions, dendrimer construction, and payload delivery (cytotoxins, targeting molecules, etc.).


Unit Size25 mg, 100 mg
Molecular Weight4490.37; single compound;
Chemical formulaC₂₀₅H₄₀₃N₅O₉₇
Purity> 95%
SpacersdPEG® Spacer is 126 atoms and 102.8 Å, avg.
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, DMSO, DMAC, DMF or Methanol.
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, 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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