Single-cell variability in growing Saccharomyces cerevisiae cell populations measured with automated flow cytometry.

Cell cultures normally are heterogeneous due to factors such as the cell cycle, inhomogeneous cell microenvironments, and genetic differences. However, distributions of cell properties usually are not taken into account in the characterization of a culture when only population averaged values are measured. In this study, the cell size, green fluorescence protein (Gfp) content, and viability after automated staining with propidium iodide (PI) are monitored at the single-cell level in Saccharomyces cerevisiae cultures growing in a batch bioreactor using an automated flow injection flow cytometer system.

Automated flow cytometry for acquisition of time-dependent population data.

Background: The implementation of flow cytometry in many experimental settings can be limited by the extensive amount of sample handling and preparation required for analysis. We describe a system that automatically performs sample handling and flow cytometric analysis, thus allowing one to construct detailed pictures of changes in cell population distributions as a function of time.

Methods: Cell samples from bioreactors were loaded into a microchamber designed to perform all sample preparation steps including washing, fixation, staining, and dilution.