dPEG®₄-biotin acid



Product number 10199, dPEG®4 biotin acid, is the precursor product of our highly popular PN10200, NHS-dPEG®4-biotin, and our increasingly popular PN10009, Biotin-dPEG®4-TFP ester. This product is a free acid rather than an active ester and can be functionalized for a variety of uses.

Biotinylation is the process of covalently attaching biotin to a molecule such as a peptide, protein, or nucleic acid, or to a surface such as glass or gold. It is widely used in bioconjugation research and product development. Biotin is normally poorly soluble in water, but the amphiphilic dPEG® linker imparts excellent solubility in water or aqueous buffer and in organic solvent. In the past, many experiments have coupled aminocaproic acid to biotin to use as a spacer between biotin and the surface to be modified. Unfortunately, aminocaproic acid (often abbreviated as LC, for “long chain”) is highly hydrophobic. Insoluble in water, LC-biotin must be dissolved in an organic solvent such as DMF or DMSO before using in aqueous buffer. When conjugated to proteins or other biomacromolecules, LC-biotin can trigger aggregation and precipitation of conjugated molecules due to hydrophobic interactions. In assays, the hydrophobicity of LC-biotin also increases background noise through non-specific binding.

Amphiphilic dPEG®4 biotin acid can be dissolved both in water or aqueous buffer and in organic solvent. It does not cause aggregation or precipitation of biomolecules. Using 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) chemistry, PN10199 can be coupled directly to free primary amines in aqueous media. Moreover, the acid moiety can be functionalized with other reactive groups for coupling to surfaces such as glass, gold, or magnetic nanoparticles. The linker length of dPEG®4 biotin acid is only slightly longer than the linker length of LC-biotin, but dPEG®4 biotin acid has far superior performance characteristics compared to LC-biotin.

This product has been used in a variety of applications that take advantage of the strong avidin-biotin binding interaction. Such applications include single cell imaging of protein secretion, developing biosensors, measuring cytokine response during inflammation, and assembling supramolecular nanostructures.

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