Dielectrophoretic separation studies were undertaken to investigate the possibility of separating cells with varying physiological character. An attempt was made to define the importance of size in the determination of separability. Living cells of Saccharomyces cerevisiae var. ellipsoideus were separated from the same cells killed by heating, using a batch separation. Cells cultured in wort broth were separated from cells grown in yeast nitrogen base – 1% glucose using both batch and continuous separators. Size analyses of separated fractions were performed using a Coulter transducer/multichannel pulse height analyzer. A size differential in cell separability was demonstrated, although it is clear that a complex function of both size and polarizability is instrumental in determining the separation of cell types.