(392j) Size Based Separation of Lipid Droplets Using Insulator-Based Dielectrophoresis

Cells store neutral lipids in cytosolic lipid droplets, which are hypothesized to form from the endoplasmic reticulum. Droplets are often “called obesity” organelles because they occupy the vast majority of the volume of adipocytes in white adipose tissue. Much information on the roles of lipid droplets has been obtained by proteomic and lipidomic analysis of isolated droplets. However, lipid droplets harvested from cultured cells can only be analyzed in aggregate. Here, we present size based sorting of lipid droplets using insulator-based dielectrophoresis (iDEP). Submicron lipid droplets from yeast cells and lipid cells from human hepatocytes and human adipocytes in the 1-10 µm range were sorted according to their sizes in a microchannel with insulating posts using insulator-based dielectrophoresis (iDEP). DEP refers to the movement of particles, due to polarization effects when particles are exposed to non-uniform electric fields. In particular, in iDEP, these electric field gradients are generated by employing insulating structured between two external electrodes.  By carefully selecting operating conditions and microdevice design, it was possible to concentrate and sort a sample of lipid droplets.