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  • Use of Ratiometric Probes with a Spectrofluorometer for Bacterial Viability Measurement.

Use of Ratiometric Probes with a Spectrofluorometer for Bacterial Viability Measurement.

Journal of microbiology and biotechnology (2018-12-20)
Jérôme Cléach, Denis Watier, Bruno Le Fur, Thomas Brauge, Guillaume Duflos, Thierry Grard, Philippe Lencel
ABSTRACT

Assessment of microorganism viability is useful in many industrial fields. A large number of methods associated with the use of fluorescent probes have been developed, including fluorimetry, fluorescence microscopy, and cytometry. In this study, a microvolume spectrofluorometer was used to measure the membrane potential variations of Escherichia coli. In order to estimate the sensitivity of the device, the membrane potential of E. coli was artificially disrupted using an ionophore agent: carbonyl cyanide 3-chlorophenylhydrazone. The membrane potential was evaluated using two ratiometric methods: a Rhodamine 123/4',6-diamidino-2-phenylindole combination and a JC-10 ratiometric probe. These methods were used to study the impact of freezing on E. coli, and were compared with the conventional enumeration method. The results showed that it was beneficial to use this compact, easy-to-use, and inexpensive spectrofluorometer to assess the viability of bacterial cells via their membrane potential.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Mitochondrial Membrane Potential Kit, sufficient for 100 fluorometric tests (flow cytometry)