Sophion Bioscience - new Patch-Clamp Technique

Patch-Clamp Technique

Patch clamp Technique
The patch clamp technique is considered the gold standard method for studying ion channel properties. In classical patch clamping a patch of an intact cell is sucked into a miniature glass micropipette so that the membrane adheres closely to the inner wall of the pipette. Application of negative hydrostatic pressure to the pipette generates an electric resistance in the giga-ohm range (gigaseal) between the rim of the pipette tip and the cell membrane. This seal becomes to tight that insignificantly few ions can flow between the pipette and the membrane. If the membrane patch encircled by the pipette orifice contains ion channels, the current through these can be studied by controlling the electrical potential of the pipette. Application of fast voltage or vacuum pulses ruptures the membrane patch, so that the saline solution in the pipette comes into direct contact with the cell cytoplasm. This so-called "whole-cell" configuration allows recording of the total current through all ion channels in the entire cell membrane. When exchanging the bath solution surrounding the cell to contain a test compound, the changes in response of all channels in the cell membrane is being recorded.

Automated patch clamp
QPatch is the name of Sophion's product family of automated patch clamp (APC) systems. Based on advanced microtechnology, QPatch systems potentially increase patch clamp throughput from 100 up to 1,000 times by means of a high degree of parallelism and automation compared to manual patch clamping. QPatch thus combines the accuracy of traditional patch clamp with the high throughput of indirect methods.

The QPatch technology is based on planar glass-coated silicon chips with micro-etched patch-clamp holes (the equivalent of the micropipettes in a conventional patch-clamp). Extra and intracellular saline solutions are applied by miniature flow channels, which ensures laminar flow and short fluid exchange times (<100ms). The walls of the flow channels are covered with glass to minimize problems with non-specific binding of "sticky" compounds.