A new technique for multiple re-use of planar patch clamp chips

The patch clamp technique is widely used for recording the activity of ion channels in single cells and lipid bilayers. Most platforms utilize borosilicate glass configured as a pipette, however more recently planar patch clamp chips have been developed that require less technical expertise. Planar patch clamp chips in systems like the Nanion Port-a-Patch are useful in that they allow more rapid throughput in drug screening studies. This technique also has the ability to perform rapid solution changes from the intracellular side. A current drawback with the planar patch clamp chips is the need to utilize a separate chip for each experiment. This increases the cost of each experiment and is due to the fact that the ∼1μm aperture used for cell attachment is thought to retain cellular debris thereby preventing subsequent cell attachment and formation of GΩ seals. In the present study we have for the first time solved the technical problem of developing a simple protocol for re-use of Nanion planar patch clamp chips. The re-use methodology is demonstrated in whole cell patch clamp studies of HEK-293 cells expressing the electrogenic sodium bicarbonate cotransporter NBCe1-A in protocols involving external and internal solution changes, and CHO-K1 cells with incorporated gramicidin channels.