Patch-clamping of primary cardiac cells with micro-openings in polyimide films

Abstract

Patch-clamping is a powerful method for investigating the function and regulation of ionic channels. Currently, great efforts are being made to automate this method. As a step towards this goal, the feasibility of patch-clamping primary cells with a microscopic opening in a planar substrate was tested. Using standard microfabrication and ion beam technology, small-diameter openings (2 and 4 microm) were formed in polyimide films (thickness 6.5 microm). Single cells (sheep Purkinje heart cells, Chinese hamster ovary cells) in a suspension were positioned on top of the opening and sucked towards the opening to improve adhesion of the cell to the planar substrate, hence increasing the seal resistance. Voltage/current measurements yielded a median seal resistance of 1.3 Mohms with 4 microm openings (n=24) and 26.0 Mohms with 2 microm openings (n = 75), respectively. With 2 microm openings, successful loose-patch recordings of TTX-sensitive inward currents and action potentials in sheep Purkinje heart cells (n = 18) were made. In rare cases, gigaseals (n = 4) were also measured, and a whole-cell configuration (n = 1) could be established. It was concluded that the simple planar patch approach is suitable for automated loose-patch recordings from cells in suspension but will hardly be suitable for high-throughput whole-cell patch-clamping with high-resistance seals.

A microfluidic device for simultaneous electrical and mechanical measurements on single cells

“…[13][14][15][16][17][18][19][20] Advances in microfluidic technologies have led to the development of microdevices for single-cell electrical property characterization. The three types of microdevices for electrical characterization are based on patch clamp, [21][22][23][24][25][26][27][28][29][30][31][32][33][34] electrorotation, [35][36][37][38][39][40] and micro-electrical impedance spectroscopy ͑-EIS͒.…”

Cell placement and guidance on substrates for neurochip interfaces

“…Consequently, there is real demand for interrogation interfaces which increase throughput, while still providing high resolution of ion channel activity. Planar patch-clamp chips suitable for use with isolated cells in suspension are under development to address these demands (Dunlop et al, 2008;Fertig et al, 2002;Lau et al, 2006;Stett et al, 2003). They all feature a planar substrate with an integrated microhole in a thin membrane separating two reservoirs (Fig.…”

High-fidelity patch-clamp recordings from neurons cultured on a polymer microchip

“…al. 2005, Stett et al 2003b. Plasma treatment of the polyimide surface followed by poly-L-lysine functionalization rendered the surface hydrophilic, thus favoring giga-seal formation.…”

“…al. 2004, Sordel et al 2006, Stett et al 2003a, silicon nitride (Fertig et al 2000, Mealing et al 2005, Py et al 2008, Schmidt et al 2000, quartz/glass (Chen et al 2009, Fertig et al 2002, Ong et al 2007, poly(dimethylsiloxane) (Chen and Folch 2006, Dahan et al 2008, Lau et al 2006 and polyimide (Kiss et al 2003, Stett et al 2003b. High throughput analysis systems have been commercialized (Bruggemann et al 2003, Dubin et al 2005, Kutchinsky et al 2003.…”