AFDye 488 Maleimide
AFDye™ 488 Maleimide (Alexa Fluor® 488 C5 Maleimide equivalent) is a green-fluorescent, water-soluble dye with pH insensitive emission from pH 4 to pH 10. This dye is ideally suited to the 488 nm laser line. AFDye 488 is one of the brightest dyes commercially available with fluorescence quantum yield close to 100%.
Maleimide is the most popular sulfhydryl-reactive reactive group for conjugating the dye to either 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 bonds. The resulting conjugates exhibit brighter fluorescence and greater photostability than the conjugates of many other spectrally similar fluorophores.
AFDye™ 488 Maleimide (Alexa Fluor® 488 C5 Maleimide equivalent) is a thio reactive, green emitting dye routinely used to label proteins or antibodies through the sulfhydryl groups (Cys), thoil-modified oligonucleotides, and other thiol-containing biomolecules. The labeling occurs most efficiently at pH 6.5-7.5 and forms a stable, covalent amide bond.
AFDye™ 488 is a water-soluble, highly photostable dye with very high fluorescence quantum yield. Its green fluorescence is pH independent from pH 4 to pH 10. The excitation of AFDye™ ideally suited for the 488 nm line. AFDye™ 488 dye conjugated to a variety of antibodies, peptides, proteins, tracers, and amplification substrates often used for generation of stable signal in imaging and flow cytometry.
AFDye™ 488 is structurally identical to Alexa Fluor® 488. Its absorption/emission spectra is a perfect match to spectra of many other fluorescent dyes based on sulfonated rhodamine 110 core, including DyLight® 488, Alexa Fluor® 488. AFDye™ 488 Maleimide can be used a less expensive alternative to Alexa Fluor® 488 C5 Maleimide.