Direct Count of Bacteria Using Fluorescent Dyes: Application to Assessment of Electrochemical Disinfection

Tadashi Matsunaga, Mina Okochi, Satoshi Nakasono

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A rapid method for direct counting of viable and dead cells using two fluorescent dyes, propidium iodide and 4 ', 6-diamidino-2-phenylindole, was developed for estimation of cell viability after electrochemical disinfection. Using this double staining method, dead and viable cells were visualized as red and blue fluorescent cells, respectively, under UV excitation employing epifluorescence microscopy. A good correlation between the red cell ratio and the ratio of dead cells determined by the plate count method was obtained for Vibrio alginolyticus cells exposed to heat (60 °C), 10 ppm of chlorine, 3.7% of formaldehyde, and electrochemical disinfection treatment.

Original languageEnglish
Pages (from-to)4487-4490
Number of pages4
JournalAnalytical Chemistry
Issue number24
Publication statusPublished - 1995
Externally publishedYes


ASJC Scopus subject areas

  • Analytical Chemistry

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