The present invention (also identified as “
Capacitance cytometry”) relates to microfluidic and nanofluidic devices for detecting or measuring an electrical property of a fluid (liquid or
aerosol), a single molecule, particle, or
cell in fluid. In a particular embodiment, the devices detect or measure changes in
capacitance of a fluid, molecule, particle or
cell as it passes through the device. The invention relates to detection and measurement of single molecules, particularly biological molecules, and to methods of sequencing
polynucleotide molecules (
RNA or
DNA) by detecting differentially labeled single nucleotides. Single molecule detection applications include
DNA or
RNA sequencing, detection of SNPs, protoemics, and particle
sizing. The device can be used to determine
cell DNA content, to analyze cell-cycle
kinetics of cell populations, and to
assay for abnormal changes in cell DNA content. Nano-microfluidic devices of this invention also have utility as detectors in molecular sorting systems and for detecting pathogens.