Evaluation of cell numbers and viability of Saccharomyces cerevisiae by different counting methods

Four counting methods (two flow cytometry, one Coulter principle, one micro scopic) are compared for measuring cell density and viability of batch-grow n yeast. All gave adequate precision in measuring total cell density with n o systematic difference between methods. However, the promise of flow cytom etry as a rapid means of determining both quantity and quality of a cell po pulation is shown.