Capacitance cytometry: Measuring biological cells one by one

Measuring the DNA content of eukaryotic cells is a fundamental task in biol ogy and medicine. We have observed a linear relationship between the DNA co ntent of eukaryotic cells and the change in capacitance that is evoked by t he passage of individual cells across a 1-kHz electric field. This relation ship is species-independent; consequently, we have developed a microfluidic technique-"capacitance cytometry"-that can be used to quantify the UNA con tent of single eukaryotic cells and to analyze the cell-cycle kinetics of p opulations of cells. Comparisons with standard flow cytometry demonstrate t he sensitivity of this new technique.