VIGOR, VITALITY AND VIABILITY OF MICROORGANISMS

Assessment of the vigour, vitality or viability of microorganisms must be done on an individual basis and thus requires the non-invasive int errogation of single organisms. For suspended organisms, flow cytometr y provides a powerful means of measurement of a wide range of characte ristics. Similar information for microbes in aggregates or growing on surfaces may be obtained by use of confocal scanning laser microscopy. For instance, membrane potential-sensitive fluorophores can distingui sh between vigorous, frail and dead cells.