XFD430 NHS ester

XFD430, manufactured by AAT Bioquest, is a green-fluorescent dye that is structurally similar to Alexa Fluor(TM) 430 (Thermo Fisher). It has excitation and emission maxima of 432 nm and 540 nm, respectively, and is efficiently excited by a 405 nm violet laser. Its large Stokes shift minimizes spectral overlap with blue-emitting fluorophores, significantly improving the signal-to-noise ratio in multiplexed fluorescence assays. XFD430 also exhibits excellent water solubility and remains pH-insensitive across a wide range (pH 4-10), making it well-suited for generating stable, reproducible fluorescence signals in both microscopy and flow cytometry applications. The N-hydroxysuccinimidyl (NHS) ester of XFD430 is a widely used reagent for the conjugation of this dye to proteins or antibodies. 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 XFD430 NHS ester an excellent choice for labeling proteins, amine-modified oligonucleotides, and other amine-containing molecules.