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Amino-dPEG®₁₂-t-butyl ester (QBD-10281)



Amino-dPEG®12–t-butyl ester, product number QBD-10281, is a carbonyl- and amine-reactive, single molecular weight polyethylene glycol (PEG) product with a discrete chain length. The compound consists of a primary amine and a propionic acid tert-butyl ester on opposite ends of a discrete PEG (dPEG®) spacer. The amine end of the molecule reacts readily with aldehydes and ketones to form reducible Schiff bases and with carboxylic acids and their active esters (NHS, TFP) to form amide bonds. A tert-butyl ester group protects the propionic acid end of the product. The ester is cleavable with trifluoroacetic acid (TFA), leaving the propionic acid moiety free to react with amines either by activation with an acylation reagent or by direct coupling to an amine using a carbodiimide.

This product can be used in peptide synthesis, protein modification, other forms of supramolecular construction, and as a novel, monoprotected heterobifunctional crosslinker. The dPEG® spacer is not a dispersed polymer with a range of chain lengths and molecular weights but a very high purity, single molecular weight PEG chain with a discrete chain length. One of the advantages of dPEG® compounds is that analyses of conjugates made with dPEG® linkers are simplified since only one chain length and molecular weight of PEG is present. Moreover, our amphiphilic dPEG® products impart water solubility to conjugates made with them, often improving the performance of the conjugate compared to the parent molecule.

Published applications for Amino-dPEG®12–t-butyl ester include the following:
Development of anti-fouling surfaces;
Creation of targeted NIR and non-peptidic SPECT imaging products to act as guides for surgical removal of cancerous growths; and,
Creation of highly specific crosslinkers for the development of antibody-drug conjugates (ADCs).


Unit Size100 mg, 1000 mg
Molecular Weight673.83; single compound
Chemical formulaC₃₁H₆₃NO₁₄
Purity> 98%
SpacersdPEG® Spacer is 40 atoms and 46.5 Å
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, 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, 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.

Surfactant-induced Polymer Sgregation to Produce Anti-fouling Surfaces via Dip-coating with an Amphiphilic Polymer. Shunsuke Yamamoto, Shigeru Kitahata, Ayane Shimomura, Kaya Tokuda, Takashi Nishino, and Tatsuo Maruyama. Langmuir. 2014. December 5, 2014. DOI: 10.1021/la5043712.

Evaluation of a Carbonic Anhydrase IX-Targeted Near-Infrared Dye for Fluorescence-Guided Surgery of Hypoxic Tumors. Peng-Cheng Lv, Jyoti Roy, Karson S. Putt, and Philip S. Low. Molecular Pharmaceutics. 2016, April 4, 2016. DOI: 10.1021/acs.molpharmaceut.6b00065.

Evaluation of Nonpeptidic Ligand Conjugates for SPECT Imaging of Hypoxic and Carbonic Anhydrase IX-Expressing Cancers. Peng-Cheng Lv, Karson S. Putt, and Philip S. Low. Bioconjugate Chemistry. 2016, 27, pp 1762-1769. June 30, 2016. DOI: 10.1021/acs.bioconjchem.6b00271.

Use of a next generation maleimide in combination with THIOMAB™ antimbody technology delivers a highly stable, potent and near homogeneous THIOMAB™ antibody-drug conjugate (TDC). Joao P M Nunes, Vessela Vassileva, Eifion Robinson, Mauricio Morais, Mark E B Smith, R Barbara Pedley, Stephen Caddick, James R Baker, and Vijay Chudasama. RSC Advances. 2017, 7 pp 24828-24832. April 28, 2017. DOI: 10.1039/C7RA04606E.

Functional native disulfide bridging enables delivery of a potent, stable and targeted antibody–drug conjugate (ADC). João P. M. Nunes, Maurício Morais, Vessela Vassileva, Eifion Robinson, Vineeth S. Rajkumar, Mark E. B. Smith, R. Barbara Pedley, Stephen Caddick, James R. Baker, and Vijay Chudasama. Chemical Communications. 2015, 51 pp 10624-10627. June 1, 2015. DOI: 10.1039/C5CC03557K.

Applicable patents and legal notices are available at legal notices.

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