Protein manipulation with insulator-based dielectrophoresis and direct current electric fields.

The present study demonstrates the manipulation of protein particles employing insulator-based dielectrophoresis (iDEP) and direct current (d.c.) electric fields. Fluorescently labeled bovine serum albumin (BSA) protein particles were concentrated inside a microchannel that contained an array of glass cylindrical insulating structures. d.c. electric fields were applied and the dielectrophoretic response of the particles was observed as a function of the suspending medium conductivity (25, 50 and 100 microS/cm) and pH (8 and 9). It was shown that the magnitude of the applied electric field (700-1600 V/cm) and suspending medium properties have a strong effect on the dielectrophoretic response of the protein particles. The results presented here are the first report on protein manipulation employing d.c.-iDEP.