Designed for Two-electrode whole-cell voltage clamping of Xenopus oocytes
The OC-725D Oocyte Clamp is designed for two-electrode, whole-cell voltage clamping of Xenopus oocytes. The dedicated design of the OC-725D includes such features as high compliance voltage (±180 V) and unique bath clamp circuitry. These same features also make the OC-725D ideal for clamping other large cells and cell structures such as squid axons. Improvements to this version include a 4-pole Bessel filter on the I Monitor output with a range of 50 Hz to 10 kHz, or full bandwidth. The electronics have been redesigned to improve efficiency and reliability.
Fast Stable Voltage Clamping
The OC-725D combines high AC and DC gains, and a voltage compliance of ±180 volts to insure fast, non-saturating clamp performance under nearly any condition. The AC clamp gain is variable up to 2000. An additional DC gain of 1 x 106 may be employed for high conductance cells (leaky oocytes).
Two clamp speeds are available: The Slow mode is used for screening oocytes or for applications not requiring fast response times. The Fast mode is used for accurate voltage clamp of fast whole cell currents. Clamp response time in the Fast mode is 550 µsec (10-90% rise time) when applying a 100 mV step to the included model cell*.
Improved Bath Clamp Headstage
The current measuring range of the OC-725D bath clamp headstage has been extended at both ends by the addition of a 3 position range multiplier. Smaller currents are amplified to usable levels and larger currents up to 1 mA can be recorded without output saturation. The unique design of the bath clamp eliminates the need for series resistance compensation. It provides an accurate measurement of bath current by creating a virtual ground in the bath while simultaneously clamping the bath potential at zero.
Voltage Headstage Probe
The voltage measuring headstage is a single-ended, high-impedance probe. Its small size, convenient mounting rod, and 2 meter cable make for easy attachment to a micropositioner. The headstage input is a 2 mm diameter pin. An electrode holder with a 2 mm jack (supplied) mounts directly on the headstage.
Voltage & Current Meters
Independent meters provide simultaneous displays of membrane voltage Vm and membrane current Im. To assure proper impalement of the current electrode, the current meter displays membrane potential Ve from the current electrode before the clamp circuit is turned on.
The internal Hold control is a ten turn potentiometer with two ranges; ±0 to 100 mV (x10) and ±0 to 200 mV (x20). External command signals applied to Command IN ÷10 are attenuated to reduce noise from the command source. Hold and external commands are summed.
*Model cell: 1 MΩ in parallel with 500nF, 1 MΩ current and voltage electrodes.
Two vented electrode holders with silver wires are typically required with the clamp; a straight type for use with the voltage headstage and a 45° type with mounting handle for use with current electrodes. Vents have been added to the electrodes to prevent pressure build-up inside the electrode which can damage oocytes. A two meter length cable assembly is provided to connect the current electrode holder to the clamp.
The OC-725D is supplied with:
Purchased separately: One straight and one 45º electrode holder is also needed and must be purchased separately
|Test Condition #1||Model cell used to obtain specifications.
Model membrane: 1 MΩ in parallel with 550 nF.
Current and voltage electrodes: both 1 MΩ impedance.
|Test Condition #2||Noise measurements made with an 8-pole Bessel filter.|
|Voltage Recording Channel (Vm)||V Probe Input Impedance||0.5 x 1012Ω, 1 pF|
|Output Resistance||100 Ω|
|DC Offset||± 200 mV at input. Variations from zero with 10 turn control (20 mV/turn).|
|Noise (0-10 kHz)||3 µV RMS with input grounded
20 µV RMS with model cell
|Electrode Test||10 mV/MΩ read on meter
100 mV/MΩ at Vm x10 output
|Meter Range||± 199.9 mV full scale|
|Current Sensing Channel (Bath Clamp) (Im)||Noise (0-1 kHz)||4.5 nA RMS with bath clamp
10 nA RMS in output leg
|I Monitor Output||1 nA/mV to 1 mA/10V in 7 steps and 3 ranges, x0.1, x1, and x10.|
|Gain Telegraph Output||0.2 to 2.8 V in 8 steps (200 mV/step) and 3 ranges, x0.1, x1, and x10.
Compatible with data acquisition software
|Meter Range, full scale||Clamp Current: ± 199.9 µA|
|Electrode Voltage (Ve)||± 199.9 mV; current meter reads Ve when clamp mode switch is off.|
|Current Electrode Channel||Compliance Voltage||± 180 V|
|Clamp Speed||550 µsec; (10-90%) with 100 mV square wave command applied to model cell|
|Gain||Variable AC/DC: 0 to 2000|
|Fixed DC Gain||Switch selected: 1 x 106|
|Ve DC Offset||± 200 mV at input (20 mV/turn)|
|Electrode Test||10 mV/MΩ read on current meter
100 mV/MΩ at Ve x10 output rear panel
|Commands||Hold||Manually set with digital potentiometer, 2 digit resolution and 2 ranges:
x10 range: 0 to ± 100 mV
x20 range: 0 to ± 200 mV
|External||Signals applied to COMMAND IN÷10 are attenuated by a factor of 10,
1 V applied = 100 mV command
|Physical Dimensions||Case||8.9 cm x 43.2 cm x 30.5 cm (H x W x D)|
|Voltage Headstage||12.5 mm D x 5 cm L with 1.8 m cable|
|Mounting Handle||8.0 mm D x 6.3 cm L|
|Bath Headstage||2.3 cm x 3.5 cm x 4.2 cm (H x W x D), with 1.8 m cable|
|Shipping Weight||6.0 kg|
|Warranty||One year, parts & labor|
|Power Requirements||Universal: 100-130 or 220-240 VAC, 50/60 Hz, 14 VA|
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(E45W, E45P) E Series Holders with Handles
(ESW, ESP) E Series Holders with Straight Body
Introduction to Premium Capillary Glass
Customers from Europe and Australia can use the Multi Channel Systems - Online Shop to order Warner products or create quotes.
Current and voltage electrode holders purchased separately
|Order No.||Model No.||Product Description||USA Price||Order|
|64-3068||OC-725D||Oocyte Voltage Clamp Amplifier||Login||Login|
|OC-725D Voltage Electrode Holder (Purchased Separately)|
|64-1009||ESW-F15V||E Series Electrode Holder, straight style, fits 1.5 mm capillary, Ag wire||Login||Login|
|64-1007||ESW-F10V||E Series Electrode Holder, straight style, fits 1.0 mm capillary, Ag wire||Login||Login|
|64-1008||ESW-F12V||E Series Electrode Holder, straight style, fits 1.2 mm capillary, Ag wire||Login||Login|
|64-1010||ESW-F20V||E Series Electrode Holder, straight style, fits 2.0 mm capillary, Ag wire||Login||Login|
|OC-725D Current Electrode Holder (Purchased Separately)|
|64-1053||E45W-F15VH||E Series Electrode Holder, 45° with handle, fits 1.5 mm capillary, Ag wire||Login||Login|
|64-1051||E45W-F10VH||E Series Electrode Holder, 45° with handle, fits 1.0 mm capillary, Ag wire||Login||Login|
|64-1054||E45W-F20VH||E Series Electrode Holder, 45° with handle, fits 2.0 mm capillary, Ag wire||Login||Login|
|64-1052||E45W-F12VH||E Series Electrode Holder, 45° with handle, fits 1.2 mm capillary, Ag wire||Login||Login|
|Accessories and Replacement Parts|
|64-0029||725-MC||Oocyte model cell||Login||Login|
|64-3070||Replacement OC-725D bath clamp||Login||Login|
|64-0033||7259C||Replacement current electrode cable for OC-725C||Login||Login|
|64-3069||Replacement OC-725D voltage headstage||Login||Login|
|64-3072||Voltage probe handle for OC-725, IE-210, IE-251, and HiZ-223||Login||Login|