76 • Reference Section
MultiClamp 700A Theory and Operation, Copyright 2000, 2001 Axon Instruments, Inc.
Clear
• Used to clear blocked microelectrodes and to assist in impaling cells in I-Clamp
mode.
• Clear is operated by alternately pressing the
and buttons in the
I-Clamp pane.
• See also Buzz.
Clear is used to pass large amounts of current down the microelectrode. Plus (+) and
minus (-) correspond to depolarizing and hyperpolarizing currents, respectively. Clear
is used for two purposes:
• Clearing blocked microelectrodes. If the microelectrode resistance in the bath
seems much higher than it should be, the electrode can often be cleared by rapidly
toggling the Clear switch from plus to minus. Because of the large current passed
this should only be done extracellularly.
• Penetrating cells. Sometimes microelectrode tips press against the cell membrane
but fail to penetrate. A quick press on the Clear buttons will often force the
electrode to penetrate. Whether to use a hyperpolarizing or depolarizing current
depends on the preparation and must be determined by trial and error. Like Buzz,
the mechanism for impalement is unknown.
To Next Page
Loading...
Need help?
General
