Ethidium monoazide bromide is a fluorescent nucleic acid stain with a photoaffinity label. The dye, after photolysis, binds covalently to nucleic acids.¹ The dye has been used to ?footprint? drug binding sites on DNA2 to modify plasmid DNA,^3,4 and to determine hemopoietic cell phenotype, function and position in the cell cycle.⁵ A particularly useful application of the dye is to selectively and covalently label dead cells in the presence of live cells. Since ethidium monoazide bromide is relatively impermeant to live cells, it selectively labels DNA in dead cells in a mixed population of live and dead cells. Photolysis following the dye application renders the dead cell DNA covalently labeled with the dye. One can then wash and fix the cell preparation and exam it by microscopy fluorescence plate reader or flow cytometry. The major advantage of this method is that researchers can avoid extensive manipulation of live pathogenic organisms.⁶

• l_ex (pH3) = 458 nm7
• Orange solid soluble in DMF, or ethanol
• Store at -20?C and protect from light, especially in solution
• C₂₁H₁₈BrN₅.
• Mwt: 420
• [58880-05-0]