Electrorotation Rates of K562 Cells Accompanied by Erythroid Differentiation Induced by Sodium Butyrate

The electrorotation (ROT) rates of K562 cells accompanied by erythroid differentiation were estimated to identify the differentiation status by using a novel electrorotation device with a microwell arranged on polynomial electrodes. Successive estimations of individual cells were achieved by sequential manipulations which involve trapping of the cell by positive dielectrophoresis (DEP), rotating by ROT, and removing by negative DEP. The ROT rate increased with the differentiation of K562 cells, because the cytoplasm conductivity would increase with an increase of the concentration of iron ions to produce hemoglobin. The ROT rate could be utilized to estimate the stage of cell differentiation without labeling.