dPEG®₄₈-biotin acid

Product number 10776, dPEG®48 biotin acid, is a 2,500 Dalton biotin acid product that contains a dPEG® spacer. Because this product is a free acid rather than an active ester, it 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®48 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, PN10776 can be coupled directly to free primary amines in aqueous media. These free amines can be on a protein, peptide, or the treated surface of a nanoparticle. Moreover, the acid moiety can be functionalized with other reactive groups for coupling directly to surfaces such as glass, gold, or magnetic nanoparticles. The nearly 180Å linker length of dPEG®48 biotin acid is far longer than the linker lengths of LC-biotin and of LC-LC-biotin. The performance characteristics of dPEG®48-biotin acid are quite superior to both LC-biotin and LC-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 characterizing protein-protein interactions, developing sensitive biosensors, measuring cytokine responses to inflammation, and functionalizing surfaces with dPEG®48 biotin.

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:
Hermanson, G. T. Chapter 11, (Strept)avidin-Biotin Systems. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 465-505.
Hermanson, G. T. Chapter 18, PEGylation and Synthetic Polymer Modification. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 787-838.

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