Automated hERG screening assay using QPatch16

NeuroSolutions Ltd. has optimized a hERG screening assay using a CHO-hERG stable cell line with Sophion's QPatch16 technology.

QPatch16 is a 16 channel automated electrophysiology platform with integrated glass-coated microfluidics which offers equivalent quality to conventional patch clamp recordings. Our automated hERG screening assay offers the following advantages:

• High quality whole-cell patch clamp recordings with 100% series resistance compensation minimizing the chance of false positive effects due to an increase in series resistance.
• Stable and low levels of leak current due to formation of glass-membrane seals with GΩ resistances (gigaseals)
• Glass-coated microfluidics prevent false negatives with 'sticky' hydrophobic compounds
• Excellent correlation of IC₅₀ data between automated electrophysiology and conventional patch clamp

To reduce adsorption of hydrophobic compounds to microtitre plates during screening, compounds can be prepared in glass-coated plates.

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Highly reproducible concentration-response relationships generated using Sophion's QPatch16. Both hydrophobic pimozide and hydrophilic verapamil give rise to reproducible IC50 data using NeuroSolutions automated hERG screening assay. IC50 curves were generated from 5 different cells. Pimozide mean IC50 = 1.98 nM, range = 1.44 - 3.02 nM. Verapamil mean IC50 = 217 nM, range 188 - 247 nM.

NeuroSolutions Ltd. offers a lower throughput hERG screening assay using a fully validated and robust HEK293-hERG stable cell line using convention whole-cell patch clamp technique. Compounds are applied through a pressurized rapid perfusion system using PTFE tubing.

Compounds can be tested using either single concentrations or concentration-response relationships to derive IC₅₀ values.

Mechanism of action studies can be performed to determine both state and frequency-dependence.