Description_x000D_ General description_x000D_ An important fluorophore prepared in high purtity with a detection limit of TMR-labeled amino acids by capillary electrophoresis of approx. 600 molecules. Readily excited by the 546 nm spectral line from mercury-arc lamps used in fluorescent microscopes, and is intrinsically more photostable than fluorescein._x000D_ Application_x000D_ 5-Carboxytetramethylrhodamine has been used in fluorophore characterization._x000D_ Biochem/physiol Actions_x000D_ 5-Carboxytetramethylrhodamine can be covalently attached to the DNA and is thereby used in studies involving branched and duplex DNA/RNA structures. It is mainly used for single-molecule studies. 5-Carboxytetramethylrhodamine is also used for the labelling of oligosaccharide for laser-induced fluorescence detection.