Electrophysiology

Electrophysiology

From our early beginnings in 1967 working with Yale researchers, electrophysiology has been at the heart of our business. WPI amplifiers, stimulators and isolators are designed with quality components so you get a reliable, low-noise signal every time. Our time-tested designs give you affordable solutions for electrophysiology equipment, electrodes, data acquisition and accessories for applications like:

• Intracellular/Extracellular Recording

• Voltage Clamp for Ussing

• Stimulation and Isolation

• Optogenetics

• Digital Filtering

Electrophysiology is study of the flow of ions in living tissue, that is the electrical properties of cells and tissues, measuring voltage change of a biological entity from a single ion channel proteins to an organ (for example, heart). Micro electrodes (glass pipette filled with an electrolyte) are placed inside a single cell for intracellular measurement and near the surface of a cell or in a preparation for extracellular measurement.

  1. Amplifiers, Electrometers
    An amplifier, in simplest terms, is an electronic device that magnifies an input signal. In this case, the amplifier magnifies the small voltage changes in cells or tissues. Not all amplifiers are created equal. The way an amplifier is designed to handle the intrinsic noise of an electronic device and the bandwidth limitations of the amplifier greatly affects the quality and sustainability of the final output signal. WPI has been designing and building amplifiers since 1967. Quality components is the key to our faithful reproduction of an input signal. WPI offers intracellular amplifiers for measurements inside a single cell, extracellular amplifiers for measurement in interstitial fluid (outside a cell), transducer amplifiers for pressure, force displacement, temperature measurements and more. The purchase of a low-noise amplifier pays dividends in the end. WPI’s amplifiers were engineered for the bio-medical researcher. While 20-30μV of noise is common in bio-amplifiers, WPI’s DAM series amplifiers generate 0.4μV RMS (root mean squared) at 0.1-100Hz. (That’s equal to about 2μV peak to peak.) The chart below compares WPI’s bio-amplifiers.An amplifier, in simplest terms, is an electronic device that magnifies an input signal. In this case, the amplifier magnifies the small voltage changes in cells or tissues. Not all amplifiers are created equal. The way an amplifier is designed to handle the intrinsic noise of an electronic device and the bandwidth limitations of the amplifier greatly affects the quality and sustainability of the final output signal. WPI has been designing and building amplifiers since 1967. Quality components is the key to our faithful reproduction of an input signal. WPI offers intracellular amplifiers for measurements inside a single cell, extracellular amplifiers for measurement in interstitial fluid (outside a cell), transducer amplifiers for pressure, force displacement, temperature measurements and more.
  2. Electrodes
    WPI offers a broad variety of standard and custom single monopolar, concentric, and stereotrode designs in a variety of tip profile and metal combinations. Some of these electrodes are also available with Rhodes style tips. WPI offers a large variety of electrodes.
  3. Electrophysiology Supplies
    These accessories (cables, connectors, footswitches, power supplies and specialty wire) are commonly used in electrophysiology applications.
  4. Glass and Holders
    Whether you are making your own electrodes or using ours, we have a variety of microelectrode holders, along with a variety of accessories for filling glass micropipettes. We even have optical quality glass bottom dishes for delicate cell work under a microscope. WPI’s microelectrode holder-half-cells couple fluid-filled glass micropipettes to high input impedance amplifiers. A Ag/AgCl pellet (or a silver wire) molded into the holder body provides stable potential. Electrical connection is made via male 2mm pins or female 2mm sockets. The pipette may be mounted axially or at right angles to the holder. Pipettes are held with screw-caps or rubber gaskets (without caps). Filling WPI microelectrode holders with electrolytes containing chloride results in stable electrode potential. Suitable electrolytes include KCl, NaCl andCaCl2. Holders are supplied for standard WPI single glass capillary tubing of 1.0, 1.2, 1.5 and 2.0mm outside diameters. (Call WPI regarding custom designs for other glass diameters.) The holder style you select will depend on your experimental application, space, and instrumentation. More Information For tips on selecting and using our micropipette holders, see Micropipette Holders and Half Cells.
  5. Microforges, Pullers, Bevelers
    When you are making your own glass micropipettes and microelectrodes, you need a few reliable appliances you can count on, including a puller for custom pulling your own pipettes, a microforge for fire polishing and a beveler for putting precise angles on your tips. More Information For an overview of this product category, see the Microforges, Pullers, Bevelers Application Guide.
  6. Specialty Instruments
    If you are looking for specialized laboratory equipment for electrophysiology, let us know. From low pass filters to micropressure systems, we have an interesting variety.
  7. Stimulators
    WPI stimulators for electrophysiology research are constant current stimulators. These are preferred over constant voltage stimulators, because: Current is the quantity that stimulates most excitable tissues. Stimulating electrodes (and some tissues) tend to increase their resistance as stimulation progresses. A constant current stimulator "senses" the resistance change and provides whatever voltage is needed to maintain delivery of current at the set rate. Stimulus isolators isolate a given stimulus from ground. WPI isolators in the 300 and DLS series offer a compliance voltage (maximum output voltage) of 100V with very low noise
  8. Stimulator Accessories
    For Electrophysiology equipment and accessories you can count on WPI. We've been building systems and components since the 1970s.
  9. Stimulus Isolators
    WPI offers a range of isolators and stimulators. Use the stimulus isolator comparison chart below to find the components that are compatible. For a better understanding for stimulus isolation, see Isolated Stimulation Explained.

In the early 70's, WPI began building amplifiers, stimulators, isolators and other electrophysiology research equipment for Yale University researchers. We've come a long way in 50 years, but one thing hasn't changed. We still set the industry standard on how quality amplifiers should be built. When you require low noise amplifiers for making sensitive life science recordings, we can help.

 

More Information

Amplifier Selection Guide 
Low Noise Amplifiers Outperform Cheap Imitations ()
Isolated Stimulation Explained
Metal Microelectrode Selection Guide

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