Extinction Coefficient Excitation Maximum: 84000;Fluorescence Quantum Yield: 0.1 TAMRA alkyne, 6-isomer is a derivative of TAMRA which is a xanthene dye with orange emission that is commonly used for oligonucleotide labeling and amino acid sequencing. The addition of the alkyne groups allows for it to be reacted with an azide for copper-catalyzed Click Chemistry. It comes in a 5- and 6-isomer.