Page 39 - Blog
- - April 24, 2013
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.
Cables
...moreOrder code Application/Description Connector A Connector B Cable Length 2851
Standard BNC cable BNC (male) BNC (male) 5 ft 2 in 3294
Ground wire for DAM80 probe Clip none 3 ft (0.9 m) 3491
Extension for any 8-pin DIN DIN (male) DIN (female) 5 ft (1.5 m) 3517
DAM50, DAM60, DAM70, shielded (two cables/pkg) Modular phone plug, 4 wire none 3 ft (0.9 m) 3578
Adapter cable for Ag/AgCl pellets 2 mm pin none 5 ft (1.5 m) 5371
Low-noise cable for microelectrode holders 2 mm gold pin 2 mm gold pin 2 ft (0.6 m) 5372
Low-noise cable for microelectrode holders 2 mm gold jack 2 mm gold jack 2 ft (0.6 m) 5373
Low-noise cable for microelectrode holders Combination pin/jack Combination pin/jack 2 ft (0.6 m) 5374
Low-noise cable for microelectrode holders BNC (male) 2 mm gold pin 4 ft (1.2 m) 5375
Low-noise cable for microelectrode holders BNC - - April 23, 2013
In this video, WPI Chemist Nikki Scafa demonstrates how to make a 0.1M solution of CuCl2 for calibrating WPI NO microsensors.
- - April 23, 2013
In this video, WPI Chemist Nikki Scafa demonstrates how to make a PBS buffer solution for use with WPI microsensors.
- - April 23, 2013
- - April 23, 2013
- - 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
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
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