Specialized Tools for Electrophysiology and Cell Biology Research

(EC-800A, EC-825A) Epithelial Voltage Clamps

Product Summary

The EC-800A and EC-825A are specifically designed for studies of epithelial transport and the electrical properties of tissue. They feature high common mode rejection, clamp speed selection, membrane resistance measurement circuitry, and a watertight headstage with model membrane


  • For studies of epithelial transport and the electrical properties of tissue
  • Membrane resistance measurement circuit
  • Clamp speed selection
  • Independent voltage and current commands
  • Watertight headstage with model membrane

Single Channel EC-800A and Dual Channel EC-825A
Epithelial voltage clamps from Warner Instruments provide accurate measurements of transepithelial voltage, short circuit current, and membrane resistance. Important features include fluid resistance compensation, membrane resistance readout, choice of voltage compliance, and small watertight preamp headstages. Operating modes include voltage clamp, current clamp, voltmeter, and resistance. The dual channel model includes an internal timer.



The EC-800A and EC-825A are state-of-the-art instruments with several unique and important design features offering more reliable recording and operator convenience.

High CMR
Differential voltage recordings are made with very high common mode rejection providing accurate measurements free from the effects of common mode potential changes of a noisy environment.

Membrane Resistance Measurement Accurate resistance measurements are made with the membrane mounted in the chamber. This measurement is made using a low frequency 2 Hz bipolar signal to avoid polarization of the membrane (ideal for monolayers). Resistances up to 200 kΩ are displayed on the meter with push-button convenience.

Clamp Speed Selection Three clamp speeds provide optimum recording conditions for a variety of applications. In Fast mode, preparations with low access resistance (small tissues or monolayers) can be clamped with speeds as fast as 10µsec. Typical Ussing chambers with larger tissues will use Medium or Slow modes for stable, oscillation free clamping.

Internal DC Command (Hold) control for both Voltage clamp and Current clamp modes.


Watertight Headstage with Model Membrane
The small compact headstage can be located close to the measurement site to keep input leads short for reduced noise pick-up. The model membrane circuit simulates a preparation to provide convenient operational checks of the clamp. Internal circuits are protected against the invasion of corrosive saline solutions by a watertight seal.



Choice of Voltage Compliance
The EC-800A has a voltage compliance of ±120 V and the EC-825A has a voltage compliance of ±50 V. The high voltage compliance of these instruments are important for studies of low resistance (leaky) epithelial cells and in applications in which long agar leads in the current passing circuit produce large voltage drops (which must be compensated). Additionally, the high compliance helps in charging large membrane capacitances typical of epithelial tissues, resulting in faster settling times and improved overall clamp performance.


External Control
The clamp can be operated by an external programmer, lab timer or computer. Logic control of clamp mode and clamp command levels is possible as well as simultaneous mixing of external linear commands.

Onboard Timer Controller
The dual channel EC-825A includes event timers (2) to provide cycle times and clamp durations up to 2000 seconds. Times are set with 2 digit thumbwheel switches and 4 position range switches. Once set, the timer will free run, eliminating the need for a computer or other external device to control the experiment.

Input Impedance 1 x 1010 Ω shunted by 6 pF
Input Voltage ±1.5 V maximum
Common Mode Voltage ±13 V maximum
Common Mode Rejection 100 dB at 60 Hz
Leakage Current 20 pA maximum
Offset Voltage Range ±120 mV
Voltage Clamp Ranges:
Int. Clamp Potentiometer ±100 mV with 10-turn control
Ext. Command ±1 V
Ext. Command Factor 1 mV/10 mV applied
Current Clamp Ranges:
Clamp Potentiometer ±1 mA
External Command ±10 mA
Command Factor 1 µA/10 mV applied
Speed 10 µs measured with model membrane
Fluid Resistance 0-100 Ω standard
Compensation Range 0-1 kΩ optional
Membrane Resistance Measurement made with 2 Hz bipolar constant current square wave
Ranges 0-2 kΩ, injected current = 10 nA
0-200 kΩ, injected current = 1 nA
Membrane Resistance 0-2 kΩ, 1mV/Ω
Output (EC-825A) 0-200 kΩ, 10mV/Ω
Panel Meter EC-800A 3-1/2 digit LCD; Voltage Range: 200 mV max; Current Range: 2000 µA max
Panel Meter EC-825A 3-1/2 digit LED; Voltage Range: 200 mV max; Current Range: 2000 µA max
Voltage Monitor x10
Current Monitor 10 mV/µA
EC-800A ±50 V
EC-825A ±50 V
Timers (A & B) EC-825A:
Range 10 ms to 1000 s, set with 2 digit resolution and 4 ranges (each channel)
Power Requirements 100-130 VAC or 220-240 VAC, 50/60 Hz, 15 VA
Physical Dimensions, H x W x D:
EC-800A, EC-800ALV & EC-825A 8.9 x 43.2 x 30.5 cm
Headstage 7.7 x 7.7 x 5 cm
Shipping Weight:
EC-800A & EC-800ALV 6.4 kg
EC-825A 9.1 kg
Warranty Two years, parts & labor


EC-825A Rear Panel
Epithelial Voltage Clamps (EC-800, EC-825A)



  1. Extracellular Protons Regulate Human ENaC by Modulating Na+ Self-inhibition
    Collier DM, Snyder PM
    J Biol Chem. 2009 Jan 9;284(2):792-8. Epub 2008 Nov 6
  2. The Cystic Fibrosis Transmembrane Conductance Regulator and Chloride-Dependent Ion Fluxes of Ovine Vocal Fold Epithelium
    Leydon C, Fisher KV, Lodewyck-Falciglia D
    J Speech Lang Hear Res. 2009 Jun;52(3):745-54. Epub 2008 Sep 19
  3. Extracellular calcium- and magnesium-mediated regulation of passive calcium transport across Caco-2 monolayers
    Davies SL, Gibbons CE, Steward MC, Ward DT
    Biochim Biophys Acta. 2008 Oct;1778(10):2318-24. Epub 2008 Jun 4
  4. Bioelectric Properties of Chloride Channels in Human, Pig, Ferret, and Mouse Airway Epithelia
    Liu X, Luo M, Zhang L, Ding W, Yan Z, Engelhardt JF
    Am J Respir Cell Mol Biol. 2007 Mar;36(3):313-23. Epub 2006 Sep 28
  5. Vitamin C transport and SVCT1 transporter expression in chick renal proximal tubule cells in culture
    Johnston L, Laverty G
    Comp Biochem Physiol A Mol Integr Physiol. 2007 Mar;146(3):327-34. Epub 2006 Dec 5
  6. Resistin-like molecule beta regulates innate colonic function: barrier integrity and inflammation susceptibility
    Hogan SP, Seidu L, Blanchard C, Groschwitz K, Mishra A, Karow ML, Ahrens R, Artis D, Murphy AJ, Valenzuela DM, Yancopoulos GD, Rothenberg ME
    J Allergy Clin Immunol. 2006 Jul;118(1):257-68
  7. Kinetics of urothelial ATP release
    Lewis SA, Lewis JR
    Am J Physiol Renal Physiol. 2006 Aug;291(2):F332-40. Epub 2006 Apr 4
  8. Role of membrane proteins in permeability barrier function: uroplakin ablation elevates urothelial permeability
    Hu P, Meyers S, Liang FX, Deng FM, Kachar B, Zeidel ML, Sun TT
    Am J Physiol Renal Physiol. 2002 Dec;283(6):F1200-7. Epub 2002 Jul 30
  9. Domain-specific purinergic signaling in polarized rat cholangiocytes
    Salter KD, Fitz JG, Roman RM
    Am J Physiol Gastrointest Liver Physiol. 2000 Mar;278(3):G492-500
  10. Endogenous ATP release regulates Cl- secretion in cultured human and rat biliary epithelial cells
    Roman RM, Feranchak AP, Salter KD, Wang Y, Fitz JG
    Am J Physiol. 1999 Jun;276(6 Pt 1):G1391-400
  11. Modulation of Cl- secretion by benzimidazolones. I. Direct activation of a Ca(2+)-dependent K+ channel
    Devor DC, Singh AK, Frizzell RA, Bridges RJ
    Am J Physiol. 1996 Nov;271(5 Pt 1):L775-84

Customers from Europe and Australia can use the Multi Channel Systems - Online Shop to order Warner products or create quotes.

Order No. Model No. Product Description USA Price Order
64-1605 EC-825A Dual channel epithelial voltage clamp, ±50V compliance, 110-250 VAC Login Login
64-3078 EC-800A Single channel epithelial voltage clamp, ±120V compliance, 110-250 VAC Login Login
Accessories and Replacement Parts
64-2299 EC825AHS Replacement headstage for EC-825A and EC-800A Login Login
64-2298 EC800HS Replacement headstage for legacy EC-825 and EC-800 Login Login
460-8090 2U Rack handle Login Login
64-3008 EC-825A cable, single - fits 1 amplifier (2 acquisition channels) Login Login
64-3009 EC-825A cable, dual - fits 2 amplifiers (4 acquisition channels) Login Login

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