m-dPEG®₂₅-TFP ester

Free amines react optimally with TFP esters at pH 7.5 – 8.0 in aqueous media. TFP esters are more hydrolytically stable in water and aqueous buffer than N-hydroxysuccinimidyl (NHS) esters. Nevertheless, in aqueous media, the rate at which the ester hydrolyzes to the carboxylic acid increases as the pH increases. Moreover, please note that reacting free amines on biomolecules with this uncharged, methyl-capped dPEG^® spacer may alter the overall charge of the resulting conjugates.

Many applications could potentially successfully use m-dPEG^®₂₅-TFP ester. Among those applications are:

• cell surface engineering;
• PK, BD, and immunogenicity profile improvements for biomolecules;
• imaging applications, by reducing background and non-specific binding and consequently increasing the signal-to-noise ratio;
• dendrimer construction;
• nanoparticle, quantum dot, and carbon nanotube surface coating; and,
• prevention of protein aggregation.

m-dPEG^®₂₅-TFP ester, product number 11290, is just one member of a broad line of methyl-terminated dPEG^® products. This line includes dPEG^® spacers containing 2 to 49 ethylene glycol units. These products terminate with propionic acid, NHS ester, or TFP ester. In addition to better stability to hydrolysis, TFP esters have proven to be superior to NHS esters for amine-reactive products. For more information on the outstanding performance of TFP esters, please see our page TFP Esters Have More Hydrolytic Stability and Greater Reactivity than NHS Esters.

Quanta BioDesign, Ltd., makes and sells single molecular weight PEG linkers and spacers with discrete chain lengths under the trade name dPEG^®. Our products are distinctly different from traditional PEG products because they are single molecular weight compounds with defined chain lengths rather than disperse polymers. However, dPEG^® products confer all of the benefits of traditional PEG products without the intractable mixture of different chain lengths and molecular weights of PEG found in traditional PEG products. To learn more about dPEG^® products, please read our “What is dPEG^®?” page. Please also visit our Frequently Asked Questions page to get answers to the questions we answer most often.