(565a) Trapping and Sorting of Bacteria in an Optoelectric Trap

Since the advent of microfluidics, non-contact particle trapping methods have been highly desired. Rapid Electrokinetic Patterning (REP) method, developed at Purdue University, has received considerable attention for controlled trapping and translation of particles. REP utilizes laser induced toroidal electrothermal flow and particle-electrode interaction for trapping particles. So far, REP has been predominantly used for trapping of abiotic micro- and nanoparticles. In this study, we demonstrate trapping of peritrichously flagellated, motile Enterobacter aerogenes cells. Conventionally, optical tweezers are used for trapping of motile bacteria. Due to motility of cells optical tweezers utilize intense laser beams which can induce photodamage to the bacteria. We experimentally demonstrate that REP can trap motile cells with four times lesser intense beam. In REP, trapping of bacteria is dependent upon their physical and dielectric properties. It allows us to sort tube shaped Escherichia coli cells from spherical Staphylococcus aureus cells.