DETECTAGENE(TM) GREEN CMF 1 KIT，D2920，Invitrogen

The DetectaGene™ Green lacZ Gene Expression Kit includes a fluorescein-based β-galactose derivative that has been chemically modified to include a mildly thiol-reactive chloromethyl group. Once inside a cell, the DetectaGene™ substrate undergoes two reactions: 1) its two galactose moieties are cleaved by intracellular β-galactosidase and 2) either simultaneously or sequentially, its chloromethyl moiety reacts with glutathione and possibly other intracellular thiols to form a membrane-impermeant, peptide-fluorescent dye adduct.