Page 21 - Product Information
- - April 23, 2013
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.
- - April 23, 2013
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.
- - April 23, 2013
EHB1 EHBF FOIMPH MBMPH5-7 MEH145 MEH1F45 MEH1R MEH1RF MEH1S MEH1SF MEH2R MEH2RF MEH2RFW MEH2RW MEH2S MEH2SF MEH2SFW MEH2SW MEH345 MEH3F45 MEH3FW45 MEH3R MEH3RF MEH3RFW MEH3RW MEH3S MEH3SBW MEH3SF MEH3SFW MEH3SW MEH3W45 MEH3W45 MEH6RFW MEH6SF MEH7 MEH7W MEH8 MEH900R MEH900S MPH1 MPH3 MPH4 MPH6P MPH6R MPH6S 2505
0.25" diameter (6.3mm)
SAE #8/32 thread x 4" (10cm)
For WPI and Märzhäuser manipulators5444
0.1875" diameter (4.8mm)
SAE #8/32 thread x 4" (10cm)
For Narishige and Zeisse manipulators - - April 23, 2013
Contributing Author: Dr. Steve Andre (Muscle Physiologist)
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:
- Sodium-potassium pump
- Relative rates of diffusion of these ions down concentration gradients
- Attraction and repulsion of opposite and like charges
Sodium/Potassium...more
- - April 23, 2013
A volt-ohm meter may apply a constant voltage of unknown current across the membrane and damage the cells electrically and also leave a chemical imbalance in the electrodes. WPI experimented with two volt-ohm meters:
- An expensive Fluke meter applies a DC voltage of 50 to 80mV, which (in a 1000Ω membrane) will pass 80µA. With a 200Ω membrane, this is 400µA.
- A discount meter puts out 500mV DC, which will pass 500µA through the membrane. With a 200Ω membrane, this is 2.5mA.
- - April 23, 2013
Cellular Organization
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:
- Proteins are the structural material used for building. They provide the shape and substance of cells, tissues, organs and living matter.
- Carbohydrates are converted to energy to fuel the cellular building process. If more energy is available than is required for a project, the carbohydrates are converted to fats for long term energy storage.
- Finally, nucleotides within the nucleus of a cell provide the blueprints for the project.
A Cell – Simplified
While a cell has hundreds of organelles and parts, we are primarily concerned with four parts of a cell. - Mitochondria – This is the powerhouse found in all cells. It’s like a tiny battery. It turns carbohydrates into usable energy for building.
- Nucleus – The center of the cell is full of DNA and RNA, the nucleotide blueprints.
- Ribosomes – These are...more
- - April 20, 2013
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
The three primary components include the Guide Cannula, the Internal Cannula and the Dummy Cannula (cap).
- WPI cannulas are beveled inside and out and then polished to remove any burrs and ensure that the inside diameter is perfectly cylindrical. This limits undesired trauma to tissue and ensures smooth operation.
- WPI offers exceptional quality at the best prices.
- Quantities of each item are kept in stock so you can order as needed.
Guide Cannulas
The Guide Cannula is a surgical grade, stainlesssteel tube that is implanted into a rodent's skull and cemented into place using dental cement and screws. It guides the Internal Cannula to the specific injection site.Internal Cannula
The Internal...more
- - April 30, 2012
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.
Understanding Part Numbers ♦ Options Available ♦ Workstation Specifications ♦ Platform Specifications ♦ Performance Data
Understanding WPI Part Numbers
The part numbers define the load, dimensions and compostion of the platform or table as shown in the graphic below. Use the codes listed under "Options Available" to complete the part number for the unit you require. For example, if you want a workstation that will support up to 800 pounds, is 24" x 36" and is made of 2" composite with...more
- - July 11, 2011
Synthetic quartz can be used in deep UV applications and is recommended for fluorescent applications, as it does not exhibit background fluorescence. Quartz cuvettes (absorbance, fluorescence and flow) are shipped individually packaged, glass cuvettes are shipped in packages of 10 cuvettes.
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