ATTO 390 NHS ester is manufactured by AAT Bioquest for research and development use. ATTO 390 is a coumarin-based fluorescent dye characterized by its high fluorescence quantum yield, large Stokes shift, good photostability, and low molecular weight. It exhibits moderate hydrophilicity and is optimally excited within the 360-410 nm range, with a mercury arc lamp (emission lines at 365 nm and 405 nm) serving as an effective excitation source. This dye is well-suited for applications in single-molecule detection and advanced high-resolution microscopy techniques, including PALM, dSTORM, and STED. Additionally, ATTO 390 is compatible with flow cytometry (FACS), fluorescence in situ hybridization (FISH), and other diverse biological assays.

NHS esters react selectively and efficiently with primary amines (such as the side chains of lysine residues or aminosilane-coated surfaces) at pH 7-9, forming stable covalent amide bonds. This property makes ATTO 390 NHS ester an excellent choice for labeling peptides and amine-modified oligonucleotides. For labeling antibodies and other proteins, we highly recommend our iFluor® dyes that are highly water soluble and are optimized for labeling proteins.