ISOLATION OF CULTURED CERVICAL-CARCINOMA CELLS MIXED WITH PERIPHERAL-BLOOD CELLS ON A BIOELECTRONIC CHIP

The separation and subsequent isolation of the metastatic human cervic al carcinoma cell line (HeLa cells) from normal human peripheral blood cells has been achieved by exploiting their differential dielectric p roperties. The isolation process is carried gut on a silicon chip cont aining a five-by-five array of microlocations. These microlocations co ntain underlying circular platinum electrodes with 80-mu m diameters a nd center-to-center spacing of 200 mu m. The surfaces of the electrode s and nonmetallized areas have been coated with a permeation layer to prevent the direct contact of cells with the electrode and also to min imize the nonspecific adhesion of the cells to the chip surface. An in homogenous ac field is applied to the electrodes to create the conditi ons for dielectrophoretic separation of cells. Cell separation using d ielectrophoresis as well as electronic lysis on a silicon chip would p rovide essential sample-processing steps which may be combined with a later multiplex electronic hybridization step in an integrated assay s ystem.