TAMRA Sulfo-NHS ester is a reactive form of bright yellow dye that used to generate a stable fluorescence signal in bioimaging. The maxima of Ex/Em values are at 554/583 nm, similar to that of DyLight 549, ATTO 550 and Cy 3. TAMRA might be excited using 543 or 546 nm laser line and displays good optical property. Sulfo-NHS esters have higher water solubility than NHS esters, thus they do not need organic co-solvent and readily react with amine-modified oligonucleotides or amino groups of proteins, i.e. the ε-amino groups of lysine or the amine terminus of nucleotides to form a stable amide bond between dye and the biomolecule. We offer TAMRA Sulfo-NHS ester for labeling of antibodies, peptides, proteins and oligonucleotide labeling and automated DNA sequencing applications.