Biotin-dPEG®₄-TFP ester




Product number 10009, biotin-dPEG®4-TFP ester, is an amphiphilic, hydrolytically stable product that reacts with primary amines better than the corresponding N-hydroxysuccinimide (NHS) ester.

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. The 2,3,5,6-tetrafluorophenyl (TFP) moiety of biotin-dPEG®4-TFP ester reacts with free primary amines, such as the amines on the side chain of lysine, forming a stable amide bond. The biotin moiety is used in labeling experiments, supramolecular construction, affinity chromatography, the creation of biotinylated antibodies, and many other applications.

The widely used product known as NHS-LC-biotin is formed by coupling aminocaproic acid to biotin and then activating the acid end of the molecule with NHS to form NHS-LC-biotin. However, NHS-LC-biotin is highly problematic, as it is insoluble in water and must be dissolved in organic media prior to use. When coupled to proteins, the linker’s high degree of hydrophobicity can cause rapid aggregation of the proteins. A variant of NHS-LC-biotin, known as Sulfo-NHS-LC-biotin, is water soluble, but it still causes rapid aggregation of proteins.

Biotin-dPEG®4-TFP ester does not cause protein aggregation. This permits experiments that require a high degree of biotin labeling without concerns about loss of protein due to aggregation. Although the product is soluble in organic solvent, dissolution in organic solvent is not required for conjugation, thus providing easier reaction setup and greater reaction reproducibility. The dPEG® linker in PN10009 is slightly longer than the aminocaproic acid linker in LC-biotin; therefore, dPEG®4-biotin provides better access of the biotin to the avidin or streptavidin binding pocket compared to LC-biotin.

PN10009 is part of a family of dPEG®-biotin reagents that provide different lengths. The active esters can be either NHS or 2,3,5,6-tetrafluorophenol (TFP), which is more reactive towards primary amines and more stable in water or aqueous buffer. The optimum pH for reaction with TFP esters is in the range of 7.5 – 8.5. Click here for an explanation of the advantages of TFP esters over NHS esters.

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