Characterization of a patch-clamp microchannel array towards neuronal networks analysis

The attempt to combine the planar patch clamping idea with the microelectrode array (MEA) concept has led to the fabrication of a patch clamp micro-channel array (PC mu CA). Such a system is thought to be a powerful framework for neuroscience research and drug screening, as a novel tool for simultaneous patch clamping of cultured cells or neurons in the same network.

A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work as a precise local perfusion system for chemicals or drugs. Electrical characterization for microholes of 2 mu m and 3 mu m revealed an access resistance of 8.09 +/- 0.84 M Omega and 3.18 +/- 0.63 M Omega, respectively.

The capacitance was 98.6 +/- 13.2 pF. The values are close to what can be expected from theory, but the capacitance is still too high for high resolution recording. The system was tested on HeLa cells: successful cell trapping with a sealing of 40 M Omega was recorded. Modification of the Si/SiO2 chip is needed in order to achieve a better sealing and long-term cell culturing in the PC mu CA remains to be tested.