Tutorials • 29
Chapter 3
6. In current-clamp mode the stray electrode capacitance can cause additional errors,
acting to filter the membrane potential signal. This error can be reduced by using
electronic compensation of the pipette capacitance.
While holding down the Ctrl key to magnify mouse movement, use glider control
to increase the Pipette Capacitance Neutralization (pF) value while monitoring
Scaled Output on the oscilloscope.
Figure 2.26
Note that, as you increase the value beyond about 3 pF, damped oscillations start
to appear at the beginning of each sawtooth (Figure 2.27). If you go further, full-
blown oscillations develop. As in the case of Rs compensation in voltage-clamp
mode, the art of pipette capacitance neutralization is to increase the neutralization
as far as possible without provoking oscillations. Further details are given in the
Reference section.
Figure 2.27
To Next Page
Loading...