Biotin-dPEG®23-MAL, product number 10785, is one of three products containing a biotin on one end and a maleimidopropyl moiety on the opposite end of a dPEG® spacer. The maleimide group is a useful, highly popular reactive group for conjugating to free thiol groups in biomolecules. This product provides a medium-length-chain, single molecular weight, discrete PEG (dPEG®) spacer between the biotin and the maleimide. Maleimide groups can be conjugated to free thiol groups in the pH range from 6.5 – 7.5, forming a stable thioether linkage. The dPEG® spacer in this product increases the hydrophilicity of the conjugate. To learn more about our dPEG® technology, please click here.

Many, varied applications that take advantage of the high streptavidin-biotin binding affinity could benefit from the use of this dPEG® product. These applications include fluorescence microscopy, atomic force microscopy, pull-down assays, bead-based assays, biotin-labeling of thiolated surfaces, affinity purification (including affinity chromatography), among many others.

To use Biotin-dPEG®23-MAL, the product should be dissolved in dry solvent and then added to an aqueous solution of the compound containing the free thiol. The water-miscible solvent N,N’-dimethylacetamide (DMAC) dried over 3Å molecular sieves is an excellent solvent to use for this purpose. For biomolecules (e.g., antibodies), care should be taken to keep the amount of organic solvent to a minimum so as not to denature the biomolecule or cause salt precipitation. Alternatively, this product can be dissolved in an appropriate buffer of pH 6.0 – 7.5.

We also sell two related products with shorter dPEG® spacers between the biotin and maleimide moieties. These products are PN10201, Biotin-dPEG®3-MAL, and PN10195, Biotin-dPEG®11-MAL. If you need bulk product in a larger package size than our standard sizes, please contact us for a quote. Our commercial capabilities permit us to manufacture this product at any scale that you need.

Application References:

  1. Hermanson, G. T. Chapter 11, (Strept)avidin-Biotin Systems. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 465-505. Click here for a review of Greg’s book and a link to purchase it.
  2. Hermanson, G. T. Chapter 18, PEGylation and Synthetic Polymer Modification. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 787-838.

Additional information

Weight .5 oz
Dimensions .75 × .75 × 2 in