TEV-200A Two Electrode Voltage Clamp


The TEV-200 is a high performance general purpose two electrode clamp. It's an ideal assay clamp for studying receptors and channels induced by injected mRNA in Xenopus oocytes.


 The TEV-200 was designed for simple operation without sacrificing the highest performance standards. Intended for use as a general purpose two electrode clamp, the TEV-200 is an ideal assay system. For oocyte assays, the TEV-200 is used to determine whether an injected message encodes for the functional unit of a receptor. This approach can be used to selectively isolate a gene before it is sequenced, characterize a receptor, and study receptors that are too complex to study in their native state.

One microelectrode (Channel 1) continuously records the actual membrane potential and that value is compared to the command potential. When voltage clamping, the other microelectrode (Channel 2) continuously passes the amount of current necessary to maintain the membrane at the command potential (determined by a feedback loop).

Whether you're new to voltage clamping or a veteran, you'll be amazed at how easy the TEV-200 is to operate. Electrode resistance determination is automated to function at the push of a button.

A convenient baseline adjustment control is included to aid in keeping the current signal within the range of your recording device.

The TEV-200 is unique in that it unites this ease of operation with paramount performance. This system features two low noise headstages for the fastest possible rise times; a clamp amplifier with a slew rate of 260 Volts in 15 microseconds; and a built in Bessel filter. In addition, the TEV-200 features a Virtual Current Monitor/Bath Clamp (VCM/BC) headstage which monitors the sum of channel currents flowing through the preparation and simultaneously maintains the bath at zero potential.

For "series" (chassis) current measurement without using a VCM/BC, there is an optional built in current monitor. This monitor is particularly useful when using iontophoresis to apply drugs because it eliminates any current due to the iontophoretic injection from your recording. Foot pedals for producing an oscillation at the tip of the electrode (buzz) are also available to aid in penetrating cells.

  • Eight (Im) Gain ranges
  • Two high speed, low noise headstage recording channels
  • Both recording channels have bridges for current passing and capacitance compensation for maximizing speed
  • Automatic clamping at resting membrane potential
  • Baseline adjustment for added convenience with high gain recording
  • Low noise Virtual Current Monitor/Bath Clamp (VCM/BC) headstage or standard series (chassis) current measurement
  • Control of Phase, Gain, and Speed (frequency dependence) of clamp amplifier
  • 145 Volts compliance (290 µA with 0.5 Megohm pipette)
  • Step Command Generator can be gated externally or with internal oscillator
  • Bath potential measurement and compensation (optional)
  • Foot pedal oscillation "buzz" generators (optional)
  • Digital meter for resistance, voltage, and current measurement
  • Includes internal 12-position One Pole Bessel Filter
  • Optional Series Resistance and Leakage Current Compensation (TEV-208)
Specifications ....


  • Record: Voltage recording and resistance testing from both channels
  • Clamp: High voltage two electrode voltage clamping

Channel 1 and 2 Probes

  • Input resistance: 100 Gigohm
  • Capacitance compensation: 0 -70 pF
  • Noise (grounded input): 4 µV RMS
  • Input leakage current: Adjustable to zero
  • Resistance test: 10 mV/Megohm (also displayed on meter as a resistance)

Clamp Parameters

  • Compliance voltage: 290 V peak to peak (145 V peak)
  • Maximum current: 10,000 µA (290 µA, 0.5 Megohm pipette)
  • Clamp gain: 10,000 maximum
  • Holding potential: Manual 10 turn dial, 20 mV per turn, selectable polarity
  • Resting potential (RMP): Two LED's enable automatic clamping to the intracellular membrane potential.

Current Measurement

  • Current filter: One pole low pass bessel filter. 3db down at 20, 50, 100, 200, 500, 1K, 2K, 5K, 10K, 20K, 50K, and 100K Hertz (Source: Virtual or chassis Ch 2)
  • Virtual current monitior 130 µA maximum with corresponding (VCM/BC-203 probe) Sensitivities (Gains): 0.05. 0.10, 0.20, 0.50, 1.0, 2.0, 5.0, 10.0 mV/nA (Telegraphs of 0.40 volts per step at rear panel BNC)
  • Series resistance (chassis): Same Ranges as Virtual shown above

Output Baseline Shift: Adjustable over entire current passing range. Affects only the adjusted output

Output Offset: Removes the portion of the current signal from the output that is independent of channel opening recorded by the selected current monitor (± 5 V)Step Command: ± 200 mV ten turn dial continous, and gated by 5 V CMOS internal 1, 10, 100 Hz oscillator

Meter Selection

  • Ch1 Vm: Channel 1 voltage, 199.9 mV
  • Ch2 Vm: Channel 2 voltage, 199.9 mV
  • IVIRT: Virtual Current Monitor 19.99 µA
  • ICH: Bath offset potential recorded from ancoptional TEV-201 headstage
  • Offset: Offset current output, 199.9 mV X scaling

Cabinet Size: 3-1/2 inches (9 cm) high, 19 inches (48 cm) wide, 10 inches (25 cm) deep

Headstage (Ch1 & 2): 3.7 cm (1 1/2") x 2.9 cm (1 1/8") x 2.3 cm (7/8")

Headstage VCM/BC203: 5.7 cm (2 1/4") x 3.2 cm (1 1/4") x 2.5 cm (1")

Power: 115 or 230 VAC, 50/60 Hz, 20 W

TEV-208 Specifications

Series Resistance Range: 0 to 2Kohm, 100mA max, 0 to 20 K, 10mA max, (ten turn dial)

Leakage Range: Infinety to 50 Kohm , ten turn pot.

Size: 1-1/2"H, 5-1/2"W, 6"D

Power: Gets power through VCM/BC-203 Bath cable

The TC-10 Temperature Controller and HCC-101 Microscope Stage

are Perfect companions to the TEV-200 System !


To view an application example showing the improved results obtained when a temperature controller is used in conjunction with a voltage clamp experiment, click here.

Download the Manual (PDF)
TEV-200A Complete with three headstages for Channel 1 (TEV-201), Channel 2 (TEV-202), and Virtual Current Monitor/Bath Clamp (VCM/BC-203) and mating BNC pin connectors (Also requires the use of two Pipette Holders: please see below). Now standard with GAIN feature(8 current gains of .05, .1, .2, .5, 1, 2, 5 and 10 mV/nA with telegraph output BNC). $4,980.00
TEV-201 Additional headstage to automatically correct for bath offset potentials when not using VCM/BC-203 $720.00
TEV-202 TEV-200A Channel 2 Headstage $420.00
VCM/BC-203 VCM/BC-203 - Virtual Current Monitor/Bath Clamp Headstage $880.00
TEV-208 Series Resistance/Leakage Current Adapter Box $1,050.00
TEV-B Buzz Option - Includes two foot pedals $150.00
HB180 Universal Pipette Holder for use with 1.0 to 1.8 mm glass 



LE16 Pipette Glass (1.65mm OD, 1.10mm ID; Borosilicate, Vial of 100, 4")



P657-5 5 Spare Pins for VCM/BC-203 $10.00
 Other Two Electrode Voltage Clamps:

Warning: This equipment is not intended for use in human applications or human experimentation.

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