The QPatch HTX and QPatch 16 are fully automated patch-clamp platforms that allow for the testing of up to 48 and 16 cells in parallel, respectively. These are medium-throughput machines great for confirming hits from larger screens and also for lead optimization. The QPatch machines offer high-quality measurements with the formation of gigaohm seals. The platform can be used to assay both voltage-gated and ligand-gated channels and utilizes stable cell lines.
Example of hERG inhibition. hERG potassium channel inhibition in the presence of various concentrations of an antiarrhythmic agent. Recordings were made on the QPatch in CHO cells stably expressing hERG voltage-dependent potassium channel. Each concentration of Quinidine was perfused for 5 minutes. A drug concentration of 10 µM shows close to complete inhibition of hERG.
Example of inhibition of hERG currents by an antiarrhythmic agent. Peak hERG currents were elicited by a ramp down from +40 mV to -80 mV.
Resulting time/current plots from QPatch HTX.
Currents were normalized to the negative control peak current and plotted as % inhibition.
Manual patch clamping is the “gold-standard” for the investigation of ion channel activity. In addition to confirming the activity of potential hits from high or medium-throughput screens, manual patch-clamping can be used to assess the mechanism of action of compounds and to determine the effects of compounds on the biophysical properties of a channel. Both voltage-gated and ligand-gated channels can be tested using manual patch-clamping. This system utilizes stable cell lines or native cells (neurons, cardiac myocytes, etc.).