Automated Patch Clamp - Manual Patch Clamp

Manual Patch Clamp

The traditional manual method to patch clamp using glass pipettes was developed by Erwin Neher and Bert Sakmann and required a highly skilled technician. The technician would position the glass pipette near a cell and apply the appropriate suction to create an electrical seal between the pipette and the cell membrane. This seal ensures a quality recording by preventing any current from leaking out between the tip of the pipette and the cell membrane. This seal is made when the membrane of the cell chemically binds with the tip of the pipette so that the inside of the pipette is only connected to the cytoplasm of the cell. This membrane-glass connection or seal is called a "gigaseal".

The technician traditionally used their mouth to provide the precise pressures required to seal it to the cell. In addition to controlling the pressure, the technician must also position the pipette at precisely the correct distance from the cell so that the membrane will seal with it. Using a micromanipulator, the pipette is moved towards the cell until the technician sees a change in the electrical resistance between the fluid inside of the pipette and the surrounding fluid (see animation). This typically requires 3–12 months of training before a technician is able to reliably record from cells. The technician is essentially performing a balancing act trying to watch and manipulate several systems simultaneously (motion, pressure, and electrical signals). Unless each portion of the process is performed accurately and with the right timing, the seal will not be formed properly and the technician will have to replace the pipette and start over.

These challenges reduce the number of recordings a technician can obtain, and significantly increases the cost. Automation seeks to reduce the time, complexity and cost of manual patch clamping.