AFDye™ 488 (Alexa Fluor® 488 equivalent) is a water-soluble, bright, green-fluorescent dye with excitation ideally suited to the 488 nm laser line. Its green fluorescence is pH independent from pH 4 to pH 10. AFDye™ 488 conjugated to a variety of antibodies, peptides, proteins, tracers, and amplification substrates often used for generation of stable signal in imaging and flow cytometry.
Maleimide is the most popular sulfhydryl-reactive 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 stable thioether bond. The resulting conjugates exhibit brighter fluorescence and greater photostability than the conjugates of many other spectrally similar fluorophores.
AFDye™ 488 Maleimide dye structurally is identical to Invitrogen’s Alexa Fluor® 488 C5 Maleimide