dPEG®₂₄-biotin acid



dPEG®24 biotin acid, product number 10773, consists of a biotin molecule conjugated to a single molecular weight polyethylene glycol chain of discrete length (dPEG®). The distal end of the dPEG® chain terminates with a propionic acid group. The terminal acid is available for direct conjugation to free amines or functionalization as an active ester. The long length of the dPEG® chain facilitates the development of biotin-based biosensors, especially in sterically crowded environments.

What is dPEG®?

The dPEG® tradename is Quanta BioDesign’s internationally recognized brand of single molecular weight PEG products of discrete chain length. These monodispersed PEG products demonstrate superior performance and simplified analytics compared to traditional polymer PEG products, which contain a broad range of chain lengths and molecular weights in a Poisson distribution. At Quanta BioDesign, we call our products’ superior performance, “the dPEG® difference.”

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What is dPEG®?

Frequently Asked Questions (about dPEG® products)

Biotinylation with dPEG® products

Biotinylation is the process of covalently attaching biotin to a molecule such as a peptide, protein, or nucleic acid, or a surface such as glass or gold. A wide range of bioconjugation research, products, applications, and clinical diagnostics employ biotinylation. Biotin acts as a labeling agent. Biotin binds with avidin and streptavidin (often shortened to (strept)avidin). (Strept)avidin labeled with a dye or other indicator permits the detection of tiny amounts of biotin-conjugated material. To learn more, please visit our page, “Biotinylation with dPEG® products.”

Biotin usually is poorly soluble in water. Conjugation to hydrophobic compounds aggravates the water solubility problem. Conjugation to an amphiphilic linker such as PEG permits the dissolution of biotin in water, aqueous media (e.g., buffers), and organic solvents.

Hydrophobic LC-biotin is problematic

Earlier biotinylation products used aminocaproic acid (often abbreviated as LC, for “long chain”) as a spacer between biotin and the surface to be modified. The conjugate is known as LC-biotin. Unfortunately, LC-biotin is a highly hydrophobic compound. Therefore, dissolution in an organic solvent such as DMF or DMSO is necessary before using it in an aqueous buffer.

When conjugated to proteins or other biomacromolecules, LC-biotin can trigger aggregation and precipitation of conjugated molecules due to hydrophobic interactions. Moreover, in assays, the hydrophobicity of LC-biotin increases background noise through non-specific binding.

dPEG®24-biotin acid offers superior performance to LC-biotin

Amphiphilic dPEG®24-biotin acid dissolves both in water or aqueous buffer and organic solvents. It does not cause aggregation or precipitation of biomolecules. dPEG®24-biotin acid couples directly to free primary amines in aqueous media using a suitable carbodiimide such as 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Also, different types of functional groups can modify the terminal acid moiety to permit the coupling of dPEG®24-biotin acid to surfaces such as glass, gold, or magnetic nanoparticles.

The linker length of dPEG®24 biotin acid is much longer than the linker length of LC-biotin. This very long linker length allows the deployment of biotin in novel applications. Such applications include the use of biotin in sterically crowded environments where it may be advantageous to have the biotin-(strept)avidin interaction take place well away from the conjugation site.

A variety of applications that take advantage of the strong avidin-biotin binding interaction use dPEG®24-biotin acid. Such applications include characterizing protein-protein interactions, developing sensitive biosensors, measuring cytokine responses to inflammation, and functionalizing surfaces with dPEG®24-biotin acid.

Bulk quantities of dPEG®24-biotin acid are available

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.

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Additional information

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