5-FAM SE

5-FAM SE (CAS No.: 92557-80-7) is a single-isomer fluorescent labeling reagent widely utilized in biomedical research for the covalent modification of peptides, proteins, and nucleotides, belonging to the class of amine-reactive succinimidyl ester dyes. It efficiently reacts with primary amine groups to form stable conjugates, enabling robust and long-lasting fluorescent tagging of biomolecules for downstream analytical applications. Mechanistically, its succinimidyl ester moiety facilitates covalent coupling to intracellular and extracellular amine-containing targets, supporting applications in protein tracking, biomolecular interaction studies, and signal monitoring. Following intracellular processing, related derivatives such as CFSE exhibit cytoplasmic fluorescence with characteristic excitation and emission profiles and can be retained within cells over extended periods, allowing dilution-based tracking of cell division and proliferation as well as migration studies in vitro and in vivo. Although not a pharmacological inhibitor or receptor ligand, its functional utility lies in sensitive fluorescence-based detection, typically applied at low micromolar concentrations depending on experimental design. Owing to its defined spectral properties and stable labeling capacity, 5-FAM SE is extensively employed in flow cytometry, fluorescence microscopy, and assay development for drug discovery, particularly in studies requiring quantitative analysis of cell proliferation, lineage tracing, and biomolecular dynamics.