More selective method of antibody labeling that reduces the possibility of the label interfering with subsequent antibodyantigen reactions. Provides an alternative when CyDye NHS Esters are unsuitable. Dyes are packaged in premeasured amounts and foilsealed to ensure consistent labelings. Cy3 and Cy5 monofunctional maleimides are particularly suitable for the selective labeling of molecules containing free sulfhydryl groups, such as cysteine residues in proteins and peptides and oligonucleotides. They are also useful in antibody labeling since the dye molecules are introduced away from the antibody binding site, increasing the chance that functionality of the labeled molecule will be unimpaired. The protocol is simple and robust, offering an alternative chemistry when either greater selectivity of labeling is required or amine labeling with Cy3 and Cy5 NHS Esters is not desirable or appropriate. Each kit contains five vials of dye, each sufficient for labeling 1 mg of protein.
