Monitoring dielectrophoretic collection of DNA by impedance measurement

Double stranded M13 phagemid DNA has been locally concentrated between interdigitated electrodes by dielectrophoresis. RF electric fields at 0.1 MHz and 1 MHz have been applied with field strengths exceeding 1 MV/m. Impedance changes were monitored by analysis of the driving signals or with an additional sensing signal applied at 1 kHz. DNA collection was found to be reflected clearly by changes in the capacitive part of the setup's impedance. This presents a new method for a label free, purely electronic detection of macromolecules.