4',6-diamidino-2-phenylindole dihydrochloride

DAPI is a popular nuclear counterstain for use in multicolor fluorescent techniques, as it binds strongly to A-T rich regions in DNA. It can be used to stain both living and fixed cells without side effects. Its blue fluorescence stands out in vivid contrast to green, yellow, or red fluorescent probes of other structures. ?ex?em (DNA-bound) = 358/461 nm; extinction coefficient: =21,000. Soluble in water at approx.. 20 mg/mL (heat or sonication may be required). This material has a purity of min. 95%. Supplied is also on request material with +99%. For applications, where a higher water solubility is preferred supplied can be DAPI as di lactate salt. References: Tanious FA, Veal JM, Buczak H, et al.; Biochemistry 1992; 31: 3103-12. Barcellona ML, Cardiel G, Gratton E; Biochem. Biophys Res Commun 1990; 170: 270-80. Kapuscinski J; J. Histochem Cytochem 1990; 38: 1323-29. Uhl GR; Methods Enzymol 1989; 168: 741-52. Kubista M, Akerman B, Nordén B; Biochemistry 1987; 26: 4545-53.