Lateral micro fluidic channels array chip fabrication for automated patch clamp application

Abstract

Traditionally, patch-clamp recording is accomplished with a micromanipulator-positioned glass pipette under a microscope. A cell membrane patch is sucked into the glass pipette and forms a high electrical resistance seal. The high cost and labor-intensive methods of conventional patch clamp have prevented the full potential of ion channels as a drug target class being fully realized. Automated patch clamp systems have recently been developed, in order to inexpensively collect large amounts of data in a shorter period of time. More common automation patch-clamp systems use microchips with tiny (1-2μm) holes in a plate instead of pipettes to create the gigaseals and record from single cells. In our previously reported works, a lateral aperture of a buried micro channel was demonstrated, which differs from the common planar patch aperture and is easier fluidic integration and packaging, higher-density array comparing with planar patch aperture. In this paper, we present the optimized fabrication process and integrated the optimized fabrication process to a new designed lateral patch-clamp array chip with 12 independent lateral patch-clamping sites for patch clamp application. At last, the new designed lateral patch clamp devices are utilized to conduct whole cell patch clamp measurements in rat insulinoma (INS-1) cells. High gigaseals (>1 GΩ) were formed between the glass capillary apertures and INS-1 cells. Steady state I-V plots elicited characteristic ion channel properties and longevity of the whole cell mode could be maintained for 1 h without any breakage of the gigaseals, which long enough to apply various compounds and ion channel drugs.