Patch Clamp Assay - Reaction Biology

Whole-Cell Patch Clamp Principle

Whole-cell patch clamp technique briefly applies large suction to a part of the cell membrane causing disruption and a closed gigaohm seal to allow the cytosol to be one sphere with the intracellular buffer chamber. Currents from the ion flux of the entire cell are measured via electrodes.

whole-cell patch clamp technique measures the activity of ion channels based on an electrode outside of the cell and inside the patch clamp devise which builds one liquid sphere with the cell cytomplasm via a rupture of the plasma membrane

Assay Details

Automated QPatch Platform

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.

hERG testing example with Qpatch for compound testing of cardiac safety 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 the drug was perfused for 5 minutes. A drug concentration of 10 µM shows close to complete inhibition of hERG.

trace of hERG currents in QPatch for compound testing of cardiac safety

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.

time/current plots for herg on qpatch for drug testing

Resulting time/current plots from QPatch HTX.

dose response curve of testing herg for cardiac safety

Currents were normalized to the negative control peak current and plotted as % inhibition.

Manual Patch Clamp Platform

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.).

Patch Clamp Assay Services

Whole-Cell Patch Clamp Principle

Assay Details

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