(372f) Spermatogenic Cells Manipulation Employing Dielectrophoresis

Dielectrophoresis (DEP) is an electrokinetic transport mechanism that occurs when particles are exposed to a nonuniform electric field. DEP has great potential for the manipulation of a wide array of bioparticles; it has been successfully used to concentrate, detect and separate virus, bacteria, yeast and parasites. Clinical applications of DEP have been also explored, demonstrating the dielectrophoretic detection of tumor cells and the sorting of red blood cells. Traditionally, DEP has been applied using arrays of microelectrodes and alternating current electric fields. However, electrode-based DEP has some drawbacks, such as the complex fabrication steps required to create microelectrode arrays and loss of afficiency due to fouling which is common when handling biological samples. An alternative is to employ insulator-based DEP, a technique, where nonuniform electric field are created by using ?obstacles? or insulting structures that distort electric field distribution. This novel DEP mode requires simples and inexpensive microdevices. In this work we report the manipulation of mice spermatogenic cells employing direct current electric fields applied across a microchannel containing an array of insulating structures. Sperm cells were stained with a DNA-intercalating dye to allow visualization. Rapid concentration and sorting of sperm cells was achieved by employing an electric field gradient. The response of the cells was analyzed by varying operating conditions: magnitude of the applied field and suspending medium characteristics. It is expected that the application of DEP for sperm cell manipulation could be used to speed up selection of sperm cell in to be used in reproductive technologies.