Mono-functional maleimides are particularly suitable for the selective labelling of molecules containing free sulfhydryl groups, such as cysteine residues in proteins and peptides and oligonucleotides.

• More selective method of antibody labelling that reduces the possibility of the label interfering with subsequent antibody-antigen reactions
• Provides an alternative when CyDye™ NHS esters are unsuitable
• Dyes are packaged in premeasured amounts and foil-sealed to ensure consistent labelings

They are also useful in antibody labelling since the dye molecules are introduced away from the antibody binding site, increasing the chance that functionality of the labeled molecule will be unimpaired.