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 Laysan Bio Inc.
Benefit of using the SVA over the SCM The succinimidyl valerate is an active NHS ester used for the PEGylation of primary amines. The reaction of the SVA with an amine forms a stable amide linkage. This reaction may be performed in an organic solution with a base catalyst or may be performed in an aqueous solution with a pH range of 8 to 9. The SVA functional group offers several benefits over the SCM functional group. Both of these functional groups are NHS esters and both form an amide linkage with a primary amine. The SVA is more stable in aqueous solutions as demonstrated by the half‐life of the active ester. Hydrolysis half‐life of the NHS esters in an aqueous solution pH 8.0 at 25°C: Ester Succinimidyl valerate (SVA) Succinimidyl carboxymethyl (SCM) Structure PEG‐OCH2CH2CH2CH2CO2‐NHS PEG‐OCH2CO2‐NHS Half‐life (pH 8.0, 25°C) 33.6 minutes 0.75 minutes The longer half‐life makes the SVA a better choice for reactions that are to be performed in aqueous solutions. Since the SCM reacts with the water so quickly that reagent favors hydrolysis over aminolysis when used in an aqueous solution. The increased half‐life also makes the SVA more stable during normal storage conditions, which gives the SVA products a longer shelf life than the SCM products. Because of the more versatile reactions conditions and the longer stability during storage Laysan suggests that customers evaluate the SVA functional group instead of the SCM functional group. If you have any questions regarding this information please email tech@laysanbio.com or call 256.586.9004. 1560 Tower Drive Arab, AL 36016
Phone: 256.586.9004 Fax: 256.586.9007