Acid-dPEG®9-NHS ester, product number 10119, is a homobifunctional, amine-reactive, monodispersed PEGylation reagent that is designed to give users tight control of crosslinking reactions. The single molecular weight, discrete-length PEG (dPEG®) chain is 31 atoms (35.7 Å) long. Both ends of this homobifunctional crosslinker possess propionic acid groups. However, one end terminates as the N-hydroxysuccinimide (NHS) ester of propionic acid, while the opposite end terminates as the free acid. This design permits users to conjugate each end of the molecule separately. The free carboxylic acid end then either remains unreacted for charge modification or crosslinks to another amino group.
Traditional Homobifunctional Crosslinkers
Homobifunctional crosslinkers join two different molecules using the same reactive group. Traditional homobifunctional crosslinkers are hydrophobic. With hydrophobic crosslinkers, aggregation and precipitation of conjugated molecules can be a severe problem. Moreover, all homobifunctional crosslinkers tend to polymerize uncontrollably. Also, when conjugating large biomolecules such as proteins, homobifunctional crosslinkers react both intermolecularly and intramolecularly. Such mixed reactions create a wide variety of products that are difficult to characterize.
What is dPEG®?
The dPEG® tradename is Quanta BioDesign’s signature branding of single molecular weight, discrete-length PEG products. Unlike traditional polymer PEG products, dPEG® products are exact monodisperse PEG products (Ð = 1). Each dPEG® linker has a single molecular weight with a discrete chain length. Moreover, we synthesize our products carefully from highly pure starting materials rather than purify them from a polymeric mixture. Much more information about our products is available on our “What is dPEG®?” page. Our “Frequently Asked Questions (about dPEG® products)” page answers the questions that our customers ask us most frequently. Please feel free to visit these pages.
How do I use Acid-dPEG®9-NHS ester?
Our dPEG® products are amphiphiles. Consequently, they dissolve in organic solvents and aqueous buffers. NHS esters react optimally with amines at pH 7.0 – 7.5. However, they hydrolyze in aqueous media, and the rate of hydrolysis depends on the pH of the solution. (Click here to read why TFP esters are superior to NHS esters.)
Therefore, Quanta BioDesign explicitly does not recommend storing this product in an aqueous buffer, even at ultracold temperatures. When dissolving Acid-dPEG®9-NHS ester in an aqueous medium, use it immediately and promptly discard all unused portions.
Dissolving this product in dry (over 3 Å molecular sieves) solvent creates a more stable solution. Recommended solvents for Acid-dPEG®9-NHS ester include acetonitrile, dichloromethane, DMSO, DMF, and N, N-dimethylacetamide (DMAC). When using DMF as a solvent, it must be free of amines that react with and inactivate the product.
This product has potential application in the following areas:
Coating nanoparticle surfaces;
Crosslinking small molecules, peptides, and biomolecules;
Modifying surface charge of conjugates (if the terminal acid is left unmodified); and,
Building supramolecular constructs through crosslinking.
Is Acid-dPEG®9-NHS ester Available in Bulk Quantities?
Yes, it is, as are all of our products.
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.
Crosslinkers typically are hydrophobic and contribute to aggregation, precipitation, and non-specific binding of crosslinked biomolecules. Traditional PEGylation reagents are disperse polymers. While polymer PEGylation reagents eliminate the problems associated with hydrophobic crosslinkers, their dispersity creates analytical issues due to the complex mixture of PEG chains that exist in these products.
Quanta BioDesign’s dPEG® products provide all of the benefits of traditional PEGylation reagents without the analytical complexity that comes from dispersity. Our dPEG® linkers and spacers provide a solution that is superior to hydrophobic crosslinkers and disperse PEGylation reagents. Why buy anything else?
Discover the dPEG® difference. Click the “Add to Cart” button to get started.