Patch recording - Cell-attached patch
If the cell moves freely with the pipette, raise the pipette and cell up from the bottom of
the dish, but keep everything submerged. If the cell is not free to move, then you can work
with the cell adhered to the dish but take great care to avoid vibration while recording.
The PC-505B controls can be set to values needed to perform your work. However, some
controls should not be moved or measurement artifacts or patch rupture can occur. These
are shown in the table below.
Voltage clamp waveforms are usually applied to the COMMAND IN BNC as externally
generated test protocols from your acquisition software. COMMAND IN inputs can be summed
with internally generated inputs. To pre-set the internal holding voltage (V
h
) to a fixed value
before beginning to record, or to reset it to another fixed value at any time during an
experiment, first set the meter to V
c
+h IN, then set the COMMANDS VOLTAGE POLARITY toggle
switch to - or +. Finally, set the COMMANDS VOLTAGE HOLDING control to give the desired voltage
reading on the meter.
The COMMANDS HOLDING VOLTAGE control can also be used as a quick check for voltage-
gated channel activity. Turn COMMAND SENSITIVITY off to disengage the external inputs and
vary V
h
in either direction.
Whole-cell recording ā Initial conditions
Once the pipette is attached to cell with a gigaseal, you can rupture the membrane
patch under the seal to gain pipette access to the cell interior. Before proceeding place the
amplifier into whole-cell mode by switching the PROBE SELECT toggle to low. Also, switch the
COMMAND SENSITIVITY toggle to x0.01.
Whole-cell recording - Rupture the membrane patch
Leave the TEST PULSE active. You can use the ZAP function or a suction pulse to rupture
the membrane patch. If using ZAP, start with a DURATION of 0.1 ms. Press the ZAP button to
activate the function and increase the duration by 0.1 ms on successive tries as necessary.
To Next Page
Loading...