Cell viability analysis is essential in biotechnology, microbiology, pharmaceutical research and industrial fermentation because it provides direct information about the health, functionality and physiological state of cell populations. Accurate discrimination between living and dead cells supports toxicity studies, bioprocess monitoring, quality control and formulation development. Classizer™ ONE, based on the patented SPES technology, combines particle size distribution with optical characterization and effective refractive index measurements to identify viable and non-viable cells rapidly, even in heterogeneous suspensions containing debris, impurities or secondary particle populations..
Compared with conventional fluorescence-based assays, SPES technology provides rapid label-free cell analysis with minimal sample preparation. Tens of thousands of cells can be automatically measured within minutes, reducing operator intervention and consumable costs.
The technique supports routine laboratory analysis as well as inline and online monitoring in industrial bioprocesses, making it particularly attractive for biotechnology, food, beverage and fermentation applications.
Optical classification of a suspension of yeast cells in water
Yeast cells (Saccharomyces cerevisiae) represent an excellent biological model for viability studies because structural changes occurring during apoptosis modify their optical properties. Classizer™ ONE measures these variations by combining particle size distribution with effective refractive index and single-particle optical characterization. Living and dead cells generate clearly separated populations within the EOS CLOUDS representation, enabling rapid identification, quantitative classification and reliable viability assessment without fluorescent labelling.
EOS CLOUDS of a mixture
of alive and dead yeast cells diluted in water. Due to the lower volume, the dead cells appear in a clearly separated area of the 2D plot.
Real-time measurement of yeast cell viability
Continuous monitoring of yeast viability demonstrates the capability of Classizer™ ONE to follow dynamic biological processes in real time. Samples exposed to increasing ethanol concentrations are continuously analysed using the Continuous Flow Analysis (CFA) module, showing a progressive reduction in viable cells as stress conditions increase. The EOS CLOUDS visualization independently tracks live and dead cell populations, allowing accurate calculation of viability percentages while supporting fermentation studies, cytotoxicity research and industrial process optimization.
