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USE OF THE PATCH CLAMP – A TUTORIAL
Axopatch 200B, Copyright 1997-1999, Axon Instruments, Inc.
It is good experimental practice to monitor both the current and the voltage. With good
current clamp, the current step should be square. In current clamp, monitoring the current
via the back-panel I OUTPUT connector as well as the voltage output via the SCALED
OUTPUT will allow you to assess the fidelity of the clamp, and to determine whether
I-CLAMP FAST or I-CLAMP NORMAL is more suited to a particular cell and electrode
combination.
Single-Channel Recording (Real Cell)
Set the front panel controls of the Axopatch 200B as follows:
PIPETTE OFFSET: About 5.0
ZAP: 0.5 ms
SERIES RESISTANCE COMP. % PREDICTION: 0 %, OFF
SERIES RESISTANCE COMP. % CORRECTION: 0 %, OFF
SERIES RESISTANCE COMP. LAG: 1 µs
WHOLE CELL CAP.: 0 pF, OFF
SERIES RESISTANCE: 0 MΩ
HOLDING COMMAND: 0 mV, toggle x1, OFF
SEAL TEST: ON
METER: Set switch to V
TRACK
MODE: TRACK
CONFIG.: PATCH
OUTPUT GAIN: α = 10 or as desired
LOWPASS BESSEL FILTER: 1,2, or 5 kHz
LEAK SUBTRACTION: ∞ MΩ, OFF
Set the oscilloscope to line triggering. Switch off any external step generators.
Insert the pipette and its holder into the input connector of the patch clamp. Be sure to
touch grounded metal before doing this to discharge any static charge that may have
inadvertently built up on you or on the holder. Be sure to support the headstage with your
other hand so that the micromanipulator will not have to absorb the force as you firmly
insert the holder. Lower the pipette into the bath. Any voltage offset between the bath
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