Tetramethylrhodamine (TAMRA) is a xanthene dye with orange emission. The dye is a FRET acceptor for FAM and is sometimes used as a quencher of FAM.
Like other xanthenes, TAMRA exists as two isomers (5- and 6-) with very similar spectral properties. This is an azide derivative of the 6-isomer of TAMRA. The azide can be conjugated with terminal alkynes using copper-catalyzed click chemistry (CuAAC) or with cycloalkynes with copper-free strain-promoted alkyne azide cycloaddition (SPAAC) reaction.