An Optimized LIVE/DEAD Assay Coupled with Flow Cytometry for Quantifying Post-Stress Survival in Yeast Cells

Area of Science:

• Microbiology
• Cell Biology
• Biotechnology

Background:

• Quantifying yeast survival is crucial in research.
• LIVE/DEAD stains with flow cytometry offer high-throughput analysis.
• Standardization is needed to ensure data quality and reproducibility.

Purpose of the Study:

• To present a standardized LIVE/DEAD staining protocol for yeast post-stress survival quantification using flow cytometry.
• To compare this method with Colony Forming Unit (CFU) assays.
• To highlight its utility in distinguishing between dead and damaged cells.

Main Methods:

• Standardized LIVE/DEAD staining with SYTO 9 and propidium iodide (PI).
• Flow cytometry analysis of treated *Candida glabrata* samples.
• Comparison of flow cytometry survival estimates with CFU results.

Main Results:

• The standardized protocol reliably quantifies yeast survival post-stress.
• Flow cytometry results were consistent with CFU for mock and lethal doses.
• At sublethal doses, the protocol indicated higher survival, reflecting earlier viability assessment than CFU.

Conclusions:

• The presented protocol is a fast, scalable, and reproducible alternative to CFU for yeast survival quantification.
• It provides complementary data to CFU by assessing viability at an earlier stage of cell death.
• This method effectively distinguishes between dead and damaged yeast cells.