Optically controlled cell discrimination and trapping using optoelectronic tweezers

Optoelectronic tweezers (OFT) provide a powerful tool for the manipulation of micro- and nanoparticles. The OFT device produces an optically controlled dielectrophoretic force, allowing complex dynamic manipulation patterns using light intensities up to 100 000 times lower than that of optical tweezers. Using OFT, we demonstrate the separation of live and dead human B cells, and the separation of HeLa and Jurkat cells. We also present, for the first time, a modified single-sided OFT device that promises to facilitate the integration of OFT and microfluidics. Unlike standard OFT, this single-sided OFT device produces electric fields that are oriented parallel to the plane of the device. We demonstrate the manipulation of polystyrene beads using this new single-sided OFT device, and discuss its capabilities.