Locally-Patterned Parylene Membrane Enables Electrical Resistance Measurement for a Cellular Barrier Consisting of < 100 Cells

We present a system for measuring electrical resistance of a cellular barrier consisting of < 100 cells. We fabricated a parylene membrane with pores etched by photolithography technique and bonded it to Polydimethylsiloxane (PDMS) wells by H2O vapor plasma treatment. This membrane separated the well into two compartments. In our system, since the placement and number of pores were easy to control, the pore-etched part of the membrane was fully covered with cells. Thus, electrical resistance was easily measured using only a small number of cells. As a demonstration of the measurement with the system, Caco-2 cells were seeded on an upper side of the membrane, and the resistance was measured using a volt-ohm meter.