PC-505B Manual, Rev. 201013
Warner
Instruments
A Harvard Apparatus Company
32
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.
Control
Control block
Setting
JUNCTION ZERO
control
COMMANDS
Do not adjust!
AUTO ZERO
toggle
COMMANDS
Leave on!
ZAP
toggle
COMMANDS
Safe
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 – 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.
