5-Carboxytetramethylrhodamine succinimidyl ester (5-TAMRA-SE) is an amine-reactive fluorescent probe. It has been used in double site-directed peptide modification to label proteinase substrates for use in FRET assays. It quenches lucifer yellow CH fluorescence by greater than 90% in uncleaved proteinase substrates, which allows for the detection of enzyme-cleaved substrates by an increase in fluorescence intensity. It has also been used in the synthesis of fluorescent derivatives of a variety of compounds, including the antibiotic ampicillin , nucleotide diphosphate uridine-5’-diphosphate (UDP; ), and the progesterone receptor antagonist RU486 (mifepristone; ). 5-TAMRA-SE displays excitation maxima ranging from 540 to 560 nm and an emission maximum of 580 nm.
