A Study of Living and Dead Yeast Cells Using Dielectrophoresis

Using a simple new physical technique, dielectrophoresis, living cells can rapidly be distinguished from dead ones, and collected separately. A detailed study using yeast cells is reported here. A comparative study of the dielectrophoresis of aqueous suspensions of living and dead yeast (Saccharomyces cerevisiae) was made over a range of frequencies, aqueous conductance, field strength, and time. The amount collected in a given period was observed to increase with field strength and aqueous resistivity except in the highest ranges where a reverse trend occurs. At high field strengths reversal of collection occurs (i.e., dispersion). The frequency responses of living and dead cells are different, enabling remarkably selective collection of living cells from a mixture of living and dead cells. Cells collected in this manner survive.