Development of a new flow cytometric procedure for the determination of single-cell growth properties in asynchronous Saccharomyces cerevisiae populations

A novel flow cytometric procedure has been developed with the aim of obtaining growth properties of individual Saccharomyces cerevisiae cells in asynchronous cultures. The method is based on labelling of the cell wall with FITC-conjugated to Concanavalin A and detection of the single cell fluorescence with flow cytometry after exposing the cells to growth conditions. Because the formation of new cell wall material in budded cells is restricted to the bud tip, exposure of the stained cells to growth conditions results in three cell types: (i) stained cells, (ii) partially stained cells, and (iii) unstained cells. This first staining has been coupled to the determination of the protein content of the individual cells, which gives a good estimation of the cell size. Analysis of the double staining patterns over time permits determination of cell age and specific growth rate of individual cell cohorts. The procedure has been tested with yeast cell populations growing at different growth rates. In this pa per we present a short overview of the data obtained