Patch Clamp Headstage

The probe is both a current to voltage converter and a voltage follower. The current to voltage converter used in voltage clamping has one of two high value resistors used for amplifying membrane currents. Below is a table of the different probes you can purchase from A-M Systems, Inc. and their feedback resistors.

Note:  For proper operation, the purchase of a Model 2400 Patch Clamp Amplifier Headstage and an electrode holder is required.

The probe has three connections, the input BNC, a ground jack, and a guard jack.

The input BNC will hold any BNC style electrode holder, and is where any input signal should be connected. The center conductor is connected through a current limiting resistor to a field effect transistor amplifier. Other than the current limiting resistor there is no other protection to the probe so care must be taken to avoid electrostatic discharges. The outer conductor of the BNC is connected to a guard circuit. The guard is a buffered version of the input voltage, so care must be taken not to ground the outer conductor of the BNC.