SERS microscopic imaging as novel tool for assessing viability and enumerating yeast cells at various stages of cell cycle in lag, log, exponential and stationary phases of growth in culture

Surface enhanced Raman scattering (SERS) microscopic imaging was employed to enumerate the yeast cells in culture. We found this imaging method as an efficient tool for easily differentiating and quantitatively enumerating yeast cell at different stages of cell-division cycle (G1, S, G2 and M phase) at various stages of growth phases namely lag, log, exponential and stationary phases in culture. Apart from enumerating the cells at different stages of cell cycle under lag, log, exponential and stationary phases, it was possible using SERS microscopy to differentiate the live cells from dead ones. The dead cells were SERS inactive and gave enhanced autofluorescence compared with the live cells, which were SERS active. The results from the present investigation suggest that SERS microscopic imaging, using silver nanoparticles (AgNPs) as a sensitive tool to enumerate the yeast cells in culture.