THE USE OF DAPI AS A REPLACEMENT FOR ETHIDIUM-BROMIDE IN FORENSIC DNAANALYSIS

Ethidium bromide is used extensively for the visualization of DNA in f orensic applications. This is usually accomplished by the addition of dye to the gel and buffer before electrophoresis or by staining the ge l after the run. In both procedures considerable ethidium bromide cont aining buffer is generated that must be decontaminated. We demonstrate that another fluorescent DNA binding dye, 4',6-diamidino-2-phenylindo le dihydrochloride (DAPI), can be used in place of ethidium bromide fo r yield and restriction gels, and to stain the visual marker of analyt ical gels. A low concentration of DAPI is added directly to the DNA. M ost of the stain is immediately bound to the DNA and remains bound dur ing electrophoresis.