Ethidium monoazide bromide is a DNA intercalating fluorescent dye that enters bacteria with damaged membranes. Ethidium monoazide bromide can be covalently linked to DNA by photoactivation. Ethidium monoazide bromide stains only dead cells. Ethidium monoazide (bromide) is a click chemistry reagent, it contains an Azide group and can undergo copper-catalyzed azide-alkyne cycloaddition reaction (CuAAc) with molecules containing Alkyne groups. Strain-promoted alkyne-azide cycloaddition (SPAAC) can also occur with molecules containing DBCO or BCN groups.
[1]. Nogva HK, et al. Ethidium monoazide for DNA-based differentiation of viable and dead bacteria by 5'-nuclease PCR. Biotechniques. 2003 Apr;34(4):804-8, 810, 812-3.