5(6)-TAMRA Maleimide [Tetramethylrhodamine-5-(and-6)-maleimide] *Mixed isomers*

Tetramethylrhodamine-5-(and-6)-maleimide is an excellent reagent for preparing orange fluorescent bioconjugates through thiol modifications of peptides, nucleotides, nucleic acids and proteins. Maleimides are among the most frequently used reagents for thiol modification. In most proteins, the sites of reactions are at cysteine residues that either are intrinsically present or result from reduction of cystines. Unlike iodoacetamides, maleimides do not react with histidines and methionines under physiological conditions.