Device for dielectrophoretic separation and collection of nanoparticles and DNA under high conductance conditions

Most dielectrophoretic (DEP) separations of cells, nanoparticles, and other entities are carried out on microelectrode arrays or in microfluidic device formats. Less work has been directed at designing pipette-type formats that would allow dipping into and recovering specific analytes from samples in microtiter plate formats. In order to address this important area, we have fabricated micropipette tip devices containing a 2% agarose gel plug, a buffer chamber, and platinum electrode as the DEP collection device, to be used in combination with separate sample wells that contain a circular gold electrode. We demonstrated that 200 nm fluorescent nanoparticles could be isolated into DEP high-field regions and separated from 10 μm fluorescent microbeads in high conductance buffer (1× PBS) by applying an alternating current at 10 kHz with a peak-to-peak voltage (Vpp) of 160 Vpp. The collected nanoparticles were then transferred to a new buffer solution. We also demonstrated the DEP isolation and separation of genomic DNA (>50 kbps) from the 10 μm microbeads in high conductance buffer (1× PBS) with transfer of collected DNA to another solution.