Use this chart for selecting Platinum Iridium metal electrodes.

The term stimulation refers to the delivery of energy of some kind to a biological tissue in order to elicit an observable response.

Although the energy used in stimulation may be chemical, thermal, mechanical or electrical, this discussion will focus on electrical stimulation. Electrical stimulation of biological tissues involves the delivery of current and voltage to the stimulation site. The two quantities are related by Ohm's law:

Choosing the right parts for your application is critical. Below you will find a table comparing many common parts to help you determine just what you need.

Luer kits contain many plastic parts made of a variety of materials. A common question is how to sterilize these parts. Common sterilizing methods include:

WPI offers a variety of precious metals and wire. The table below compares the specifications of the various wires. The following hints are offered to help you understand the part number codes and choose the wire you need:

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 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.

In this video, WPI Chemist Nikki Scafa demonstrates how to make a PBS buffer solution for use with WPI microsensors. 

In this video, WPI Chemist Nikki Scafa demonstrates how to make a 0.1M solution of CuCl₂ for calibrating WPI NO microsensors.

The WPI cannula system for neuroscience study and pre-clinical research includes an entire range of cannula options. You are guaranteed:

• Exceptional Quality
• Best Prices
• Rapid Order Response

It is common for a researcher to attach a camera to a microscope. Three types of cameras are available, and two are suitable for microscopy work:

These instructions describe how to properly focus a binocular microscope.

The World Precision Instruments (WPI) EVOM² is used for making trans epithelial electrical resistance (or TEER) measurements. We recommend that you test your EVOM2 before you use it for the first time and then periodically after that. If there is a concern that the meter or the electrode is not functioning properly, test the meter first. This video shows how to test the meter.

In this video, Nikki demonstrates how to prepare and fill a 2mm biosensor and prepare to calibrate an ISO-OXY-2 oxygen sensor. 

In this video, WPI Chemist Nikki Scafa demonstrates how to calibrate the WPI ISO-HPO100 hydrogen peroxide microsensor. 

The World Precision Instruments (WPI) EVOM2 is used for making trans epithelial electrical resistance (or TEER) measurements. Two silver/silver chloride pellets are used for the electrodes. The chloride ion tends to migrate, which is a reversible reaction. But, because of this chloride ion swapping, the electrodes need to be polarized before each use. Before using the meter for making voltage measurements, equilibrate the electrodes. This video shows you how.

Take a look at the variety of microelectrode holder available for your applications.

When building any structure, whether it’s a bridge or a protein, three elements are required:

• Building materials
• Energy
• Building plans

The same is true in biological systems:

All living cells maintain a difference in electrical charge between the solutions that are inside and outside the cell membranes. The voltage difference across the cell membrane is usually at a steady level known as the resting membrane potential. The resting membrane potentialis produced by the differential distribution of ions on either side of the membrane. In muscle fibers, the potassium concentration inside the cell is over 50 times greater than the ion’s concentration in the extra­cellular fluid. On the other hand, the concentration of sodium is 10 times greater outside the membrane than inside. The concentration gradient of potassium is greater and in the opposite direction to the sodium concentration gradient. The ion concentrations are governed by three factors:

WPI offers both vibration free workstations and platforms, and each is custom-built to meet your specifications. This article describes the options available and how to request a price quote for the unit you need.

The vibration-free platform looks like the one shown (left). The workstation tables are similar. These vibration-free units offer vertical and horizontal vibration isolation, high performace active-air suspension and automatic leveling. The diagrams below show dimensions of the workstations.

This chart allows you to compare the various spectroscopy cuvettes that are available in nine different styles.

WPI sensors have been selected for use in the space shuttle by the European Space Agency. After six months evaluating numerous sensors of various worldwide companies, the European Space Agency chose WPI sensors for pilot experiments in its space shuttle. WPI President, Cliff Bredenberg and Chief Scientist, Dr. Xueji Zhang will visit Italy in July to finalize the sensors and electronics design.