Caution

This product is sensitive to moisture. The vial is packaged in a resealable bag with a desiccant to reduce exposure to moisture. After cold storage, equilibrate the vial to room temperature before opening to reduce condensation inside the vial. Make fresh solutions. Storage of stock solutions is not recommended. After use, return the vial to the resealable bag. Close the bag and store the product at the recommended temperature.

Features and Benefits

Reactive groups: sulfo-NHS ester and maleimide Reactive towards: amino and sulfhydryl groups Sulfo-NHS ester end couples with primary amines at pH 7-9 to form stable amide bonds Maleimide reacts with -SH groups at pH 6.5-7.5, forming stable thioether linkages Non-cleavable Water-soluble (compare to EMCS) Aliphatic spacer offers low potential for eliciting an immune response

General description

EMCS and its water-soluble analog Sulfo-EMCS are heterobifunctional cross-linkers that contain N-hydroxysuccinimide (NHS) ester and maleimide groups that allow covalent conjugation of amine- and sulfhydryl-containing molecules. NHS esters react with primary amines at pH 7-9 to form amide bonds, while maleimides react with sulfhydryl groups at pH 6.5-7.5 to form stable thioether bonds. In aqueous solutions, hydrolytic degradation of the NHS ester is a competing reaction whose rate increases with pH. The maleimide group is more stable than the NHS-ester group but will slowly hydrolyze and also lose its reaction specificity for sulfhydryls at pH values > 7.5. For these reasons, conjugation experiments involving these cross-linkers are usually performed at pH 7.2-7.5, with the NHS-ester (amine-targeted) reaction being accomplished before or simultaneous with the maleimide (sulfhydryl-targeted) reaction.