Ethidium bromide monoazide

A possibility for differentiating between viable and nonviable cells uses ethidium bromide monoazide (EMA), a DNA binding dye that is used for the differentiation of living and dead cells in flow cytometry and PCR. Dead cells have membrane damage EMA penetrates and binds covalently to the bacterial DNA. This binding inhibits the amplification of the bound DNA so that the polymerase is sterically hindered (Wang Levin, 2005). 

Gu, W Levin, R. E. Quantification of viable Plesiomonas shigelloides in a mixture of viable and dead cells using ethidium bromide monoazide and conventional PCR. Food Biotechnol. 2007, 21, 145-159. 

A judicious choice of reagents can lead to different reactions on the external surfaces and the interiors of crystals. Hupp and coworkers investigated tandem reactions starting with the (trimethylsilyl)ethynyl-functionalized MOF [Zn2(tcpb)2(L )] (tcpb= 1,2,4,5-tetrakis(4-carboxyphenyl)benzene). They showed that the trimethylsilyl groups on the crystal surfaces could be removed by reacting with aqueous potassium fluoride and that the primary alkyne products underwent copper-catalyzed [3-f2] cycloaddition reactions with ethidium bromide monoazide (equation 4). ... 

Other vital stains take advantage of different cellular properties which can be correlated with cellular physiology Propidium Iodide, Ethidium Bromide, Ethidium Monoazide, Calcofluor White have been widely used to indicate the presence of dead eukaryotes or prokaryotes cells. 2-(p-iodophenyl-)3)(p-nitro-phenyl)-5-phenyl tetrazolium chloride (INT) belongs to a class of stains which can be used to determine if a cell or hyphal compartments [180] can maintain an internal reducing environment (Fig. 20a). There are, however, still a large debate about the reliability of those techniques, depending upon the cells under consideration [181]. Calcofluor (Aex = 380 nm, Aem 420 nm) is a specific cell wall stain which enables to counts buds scars on Saccharomyces cerevisiae [29] to estimate the age of a cell. 

Fluorescently labeled plasmid can be quite useful for cellular uptake and distribution studies (112). The main concern with fluorescently tagged DNA is that the presence of the dye molecules may interfere with the interactions between the DNA and the carrier, or the DNA and cellular components. Of equal importance, the binding of the dye to the DNA must be irreversible, so that the dye molecules do not dissociate from the DNA once internalized by the cell. A number of fluorescent DNA-intercalating dyes are available for DNA labeling, such as ethidium bromide, ethidium monoazide, the TO-PRO series, various other cyanine dyes, and many others (82). For example, the membrane-impermeable compound YO-YO... 

Hein, I. Hekna, G. Wagner, M. Possible errors in the interpretation of ethidium bromide and PicoGreen DNA staining results from ethidium monoazide-treated DNA. Comments. Appl Environ. Microbiol 2006, 72, 6860-6861. 

Fig. 3. FACScan analysis of C8166 cells. C8166 cells infected with HIV-1, 4 d postinfection, were stained with (A) control FITC-conjugated isotype antibody, (B) ethidium monoazide bromide (EMA), (C) HIV-specific anti-p24 FITC-con-jugated MAb, and (D) dual stained with EMA and anti-p24-FITC. Dual staining allows determination of the proportion of cells that are either live or dead or infected or uninfected and hence the proportion of cells that are both dead and infected, dead and uninfected, live and infected, or live and uninfected. Comparison of the proportion of cells that are dead/live/infected/uninfected with potential antiviral drug-treated and untreated cells will give an indication of whether the drug is selectively toxic for virus-infected cells or cytotoxic regardless of infection. Data were acquired on a Becton Dickinson FACScan and analyzed using WinMDI software.

Other Names Phenanthridinium, 3-amino-8-azido-5-ethyl-6-phenyl-, bromide Ethidium monoazide Ethidium monoazide bromide... 

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