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Product Information
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April 29, 2013
Microscopes are a standard laboratory tool, but purchasing the right microscope for a particular application can be a challenge. First, consider how you will use the instrument. Are you looking at slides, dissecting a small animal or performing a surgery? (The application dictates the necessary working distance and power of magnification.) What kind of a stand will you be using? (Boom stand, articulating arm or post stand) Will the microscope be used in a classroom setting? (A trinocular scope offers the option of including a camera.) Will you need a camera? (A camera allows you to project the microscope...more
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April 29, 2013
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April 26, 2013
Isolated Stimulation and Stimulus Isolators
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:
V=IR
Where V is the applied voltage, I is the current and R is the electrical resistance of the tissue and or the stimulating electrodes. This simple equation shows that if voltage is constant, current flow will diminish if the tissue/electrode resistance goes up, and will increase if the resistance decreases.
More commonly, the resistance of tissue differs from sample to sample, and the resistance...more
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April 26, 2013
NOTE: A heat treated tip is ideal for penetrating tough membranes. (It is not recommended for chronic implantation.) This process is performed using a microforge in which the heating element is positioned in close proximity to the tip in order to melt the Parylene-C distal to the exposed metal. It provides a smooth transition and produces better adherence of the Parylene-C to the metal. Both the KT and non-KT electrodes are heat-treatable. The heat treatment is applied only to the parylene coating. The heat melts the parylene so it feathers down close to the shank near where the tip is exposed. This removes the abrupt edge where the parylene has been removed to create the tip exposure. The purpose is to prevent the parylene from delaminating from the electrode during implantation into tissue which could catch on the edge. Heat treatment does not work well in chronic applications, because the feather edge is susceptible to fluid intrusion overtime, which will alter the impedance characteristics...more
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April 26, 2013
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April 26, 2013
Introductory Assortments
Each of these assortment kits includes electrodes with different impedance within each style. Use an assortment kit to determine which electrode you need for your experiment. Each box includes the electrodes listed. There are no mix and match assortment kits.
Profile A
Profile B
Profile C
Assortments Profile A Comparison Chart
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April 26, 2013
Superior microelectrodes for outstanding extracellular recording — tungsten, iridium, platinum-iridium, and Elgiloy®
Types of Metal Electrodes
WPI offers a large variety of metal electrodes and they come in three basic styles (profiles). The selection guide that follows references the three electrode profiles. In addition, concentric bipolar electrodes are also discussed, as well as some of the options offered for the metal electrodes.
NOTE: The electrode diagrams below are not shown to scale.
Profile A
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April 26, 2013
Eliminate the cost and trouble of making your own micropipettes — WPI can quickly supply your need for consistently sized pre-pulled glass micropipettes for injection of dyes or proteins into cells, oocytes and for many other biomedical laboratory applications. Tip diameters (ID) range from 0.1 to 10 micrometers. Micropipettes are available as plain shank or with luer fittings. - Schott Duran borosilicate glass
- 0.5 micrometer and smaller ID micropipettes include an internal glass fiber for easy filling
- Tip inner diameter tolerance ±20%
- Short taper yields high strength
- Nominal length ≈ 50 mm
- OD:ID = 1.33:1
- Standard capillary outer diameters are 1.0 mm (thin-wall) or 1.14 mm
- Every pipette individually tested and inspected
- Vacuum packed
Silanized Tips (Luer Shank)
Silanization waterproofs the glass to retard water when inserting into cell. This will not let...more
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April 26, 2013
The 14011 barbed tubing assortment kit contains over 250 items. All the items are pictured on a grid below. The darker lines in the image grid represent centimeters, and the smaller ones are 2.5mm apart...more
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April 26, 2013
A 4-way stopcock allows for 360 degrees of rotation and has the states (shown below) for each of the four available positions. A 3-way stopcock has only three positions and has the first three states shown below. In the first state, liquid flows between points A and B.
In the second, it flows between points A and C.
In the third, it flows between points B and C.
In the fourth state (4-way only), it flows between all three points.While they are sold in the popular kit 14011, they are also sold separately:
- 14035-10–4-way Stopcock...more
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April 26, 2013
WPI offers an array of metal microelectrodes. In this guide, we will look at introductory assortments, concentric electrodes, profile A, profile B and profile C electrodes. For basic information on these types of metal electrodes, see the Metal Microelectrode Basics page. Links to these related posts appear below this article.
Eligoy Steel is a *Cobalt/chromium/nickel alloy.
Deciphering Part Numbers
With few exceptions, the WPI metal electrodes conform to a part number standard depicted below. For the part number shown, you can determine that:- Metal - The electrode is made of platinum iridium. (See the metal codes below.)
- Length in inches - It is 2" long.
- Coating Thickness in microns - It has a 3µm coating.
- Core shaft diameter in millimeters - "B" electrodes with Kapton coating are 0.356mm.(See the core shaft...more
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April 25, 2013
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:
- EtO (gas)–a chemical steriliant small enough to penetrate the microbial cells that destroying nuclear cell components
- 70/30 Alcohol
- ...more
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April 25, 2013
The physical properties of glass depend upon the chemical composition of the glass, as well as how the glass was manufactured. Glass has no set melting point, but four temperatures are of primary importance when discussing glass production.
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Working Point - This is temperature that the glass is soft enough to work. At this temperature, the glass viscosity is 104 poises.
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Softening Point - At this temperature, glass deforms easily, even by forces of gravity. The glass viscosity is 107.6 poises.
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Annealing Point - When glass reaches the annealing point and remains for a few minutes, many of the internal stresses of the glass formation are obviated. During the annealing process, the glass is heated to the annealing temperature and then allowed to cool at a controlled rate. Glass that is not annealed is prone to crack or shatter with minor temperature fluctuations...more
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April 25, 2013
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:
- Micro coaxial cables (MAXxxxx) are ideal for microelectrode fabrication and construction of similar research tools. The dual shielding eliminates electrical interference caused by radio frequencies (RF), electrostatic and microphonics (e.g., bending and vibration). Available with single or dual (twin) conductors.
- Thermocouple wire is for temperature monitoring. TCK3050 has a chromel/alumel pair, for use in inert or oxidizing atmosphere at 1500-1800 °F.
- Teflon-coated stainless steel (type 304) wire (SSTxxxx) is available in 25-ft and 50-ft lengths. The Teflon coating is 4µm thick.
- Carbon wire (C3005) is a single 30µm...more