Analyzing cell viability

Cell viability refers to the percentage of living cells within a total population. Determining yeast cell viability is often used to investigate the effects of various stressors, both in toxicity studies and in industrial microbiology studies. The yeast Saccharomyces cerevisiae (better known as baker's yeast or brewer's yeast) is a commonly used model organism for research into the effects of chemical, physical or environmental factors on cells. Analyzing cell viability is also crucial for industrial processes involving microorganisms used in the production of food, beverages and biofuels. The Classizer™ ONE provides accurate estimation of cell viability even in the presence of secondary populations and impurities.

Compared to currently available fluorescent kits, SPES offers major advantages:

automatically performs reliable measurements of tens of thousands of cells.
is not time-consuming: each measurement takes less than a few minutes.
no expensive consumables are required.
limited or no sample preparation is required other than simple and automatable dilution.
provides in-line/online monitoring for industrial processes.

Example: mix of living and dead yeast cells

Yeast cells are optically elliptical particles with a narrow size distribution and a peak around 4 μm. A yeast cell can die by uncontrolled or regulated death (apoptosis). When dying, the cell shrinks by about 25-28% of its volume. The loss of fluid also increases the refractive index of the cell. This effect can be clearly observed and studied with the SPES technique in an aqueous yeast suspension.

Figure right: EOS CLOUDS sample of a mix of live and dead yeast cells.

Example: Real-time monitoring of live and dead yeast cells

Classizer™ ONE can perform real-time monitoring of an in-line production process to continuously determine sample differences with the CFA (Continuous Flow Analysis) add-on. In this example, ethanol is added to a sample of live yeast cells in water and then the mixture is measured continuously for 20 minutes. An area corresponding to the position of the living cells is selected on the two-dimensional histogram to calculate the percentage of measured particles within that area.

Figure left: Evolution of living cells in a water/ethanol mixture in increasing percentages of ethanol.

More information about the CLASSIZER™ ONE from EOS for cell analysis?

Contact the particle characterization specialists at Inventech.

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Analyzing cell viability

The specialists from Inventech are happy to help you find the right analytical instrument for cell analysis.