AFDye™ 532 Maleimide (Alexa Fluor® 532 C5 Maleimide equivalent) is a water-soluble, photostable, bright yellow-fluorescent dye with pH insensitive emission from pH 4 to pH 10. The excitation of AFDye™ 532 is ideally suited for the frequency-doubled Nd:YAG laser line. AFDye™ 532 dye can be conjugated to a variety of antibodies, peptides, proteins, tracers, and amplification substrates, and is often used for the generation of stable signals in imaging and flow cytometry.
Maleimide is the most popular sulfhydryl-reactive group for conjugating the dye to a thiol group on a protein, oligonucleotide thiophosphate, or low molecular weight ligand. The maleimide group specifically and efficiently reacts with reduced thiols (sulfhydryl groups, –SH) at pH 6.5 to 7.5 to form a stable thioether bond. The resulting conjugates exhibit brighter fluorescence and greater photostability than the conjugates of many other spectrally similar fluorophores.
AFDye™ 532 Maleimide dye is structurally identical to Alexa Fluor™ 532 C5 Maleimide sold by Thermo Fisher Scientific.