Mixed isomers of carboxytetramethylrhodamine (TAMRA) free acid. The dye can be coupled to primary or secondary amines via standard peptide chemistry.        λEx/λEm (MeOH) = 540/565 nm    Dark red solid soluble in DMSO, DMF, MeOH, or pH >6.5 buffer    Store at -20°C and protect from light    C25H23ClN2O5    MW: 466.92