4-(N-Maleimidomethyl)cyclohexanecarboxylic acid N-hydroxysuccinimide ester (SMCC) is useful for the preparation of enzyme immunoconjugates and hapten carrier molecule conjugates. It has been used for the coupling of a peptide sequence to an amino group.
4-(N-Maleimidomethyl)cyclohexanecarboxylic acid N-hydroxysuccinimide ester (SMCC) is a heterobifunctional cross-linking reagent incorporating an extended spacer with amine and sulfhydryl reactivity.
 It is typically coupled initially to molecules containing primary amine by amide bond buffered at pH 7.5 (6.5-8.5). The second coupling is specific for molecules containing free sulfhydryl by thioether linkage buffered at pH 6.8 (6.5-7.0). SMCC contains nine atom linker. An extended aliphatic spacer stabilizes the maleimide prior to coupling compared to aromatic spacers.
 Newton GL, et al. Determination of biothiols by bromobimane labeling and high-performance liquid chromatography. Methods Enzymol. 1995;251:148-66.
 Kosower EM, et al. Bromobimane probes for thiols. Methods Enzymol. 1995;251:133-48.