INSTRUMENT OPERATION
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Chapter 6
Zap
In order to go from cell-attached patch clamping to whole-cell patch clamping it is
necessary to rupture the patch. This is normally done by carefully controlled suction.
Another, easier to apply, technique for rupturing the patch is ZAP. ZAP works by applying
a large hyperpolarizing voltage (1.3 V
DC
) to the patch for a controlled duration. This often
causes dielectric breakdown of the membrane.
Suggested Use
Apply a repetitive test command (e.g., Seal Test). Start with Duration = 0.5 ms. Press
Trigger to ZAP the membrane. Successful zapping is accompanied by an increase in the
current noise and by large capacitance-charging current transients in response to the test
command. Use the briefest Zap that will rupture the membrane. Too long a Zap could
cause the seal resistance to deteriorate.
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