DNA/RNA Quantification Using DIPUV-Mini and a Tidas Spectrometer
Concentrations of DNA in solution (31µg/mL and 688µg/mL) were measured with a spectrometer and UV/VIS light source in a DIPUV-Mini. Due to the 2mm pathlength, use of a DIPUV-Mini does not require a pre-measurement dilution within this concentration range, thus a potential source of error was eliminated.
Metal Electrode Selection Guide for Profile B
Use this comparison chart to choose Profile B Microelectrods. They are Tungsten Profile B, 76 mmlong wiht a 0.216 mm shaft.
Nanoliter Troubleshooting
The Nanoliter injector is a micro-processor controlled injection system that uses direct piston displacement. The collet assembly (exploded view) is shown in the image below. The glass pipette fits into the white, plastic sleeve (spacer). When the collet is screwed in place securely, the black rubber washers are compressed and hold the glass firmly in place.
Understanding Microscope Objectives
A variety of microscope objectives are available. All objectives use lenses to focus light. Light is broken down into various wavelengths (colors) as it travels through a lens. The various wavelengths have different focal points. That means that red, green and blue appears to focus at different points. This is called chromatic aberration. Spherical aberrations are focal mismatches caused by the shape of the lens. Quality lenses are designed correct for chromatic and spherical aberration to bring the primary colors to a common focal point. These terms may help you determine the best objective for your application:
EVOM2 Remix
EVOM was the first instrument designed to perform routine Trans Epithelial Electrical Resistance (TEER) measurement in tissue culture research. EVOM2 is the next generation, redesigned for greater usability.
Choosing a Temperature Probe
When precise temperature measurements are required, WPI can provide you with a very accurate monitor and thermocouple microprobes. WPI monitors have both resolution and accuracy of 0.1°C in the 0-50°C range and are traceable to NIST standards, whereas, other competitive electronic thermometers have an accuracy that is usually to 0.5°C or worse. Furthermore, all our type T clinical probes are guaranteed accurate to 0.1°C, due to our stringent wire standards. These are five times more accurate than competitive probes made with regular “Special Limits” wire.
WPI's Low-Noise Amplifiers Outperform Cheap Imitations
An amplifier, in simplest terms, is an electronic device that magnifies an input signal. However, the way an amplifier is designed to handle noise and bandwidth limitations greatly affects the quality and sustainability of the final output signal.
Stimulator/Isolator Comparison Chart
WPI offers a range of isolators and stimulators. Use the chart below to find the components that are compatible.
Setting up OxyMicro and OxyMini
Oxygen measurement is simpler than ever. Just stick a disposable, oxygen-sensitive "spot" to the inside of a flask, beaker, test tube or bottle, and fill the container with the solution to be tested. Then, on the outside of the glass container, hold the fiber optic wand close to the spot to take a reading. As the spot reacts with oxygen, it gives off light, which is measured with the fiber optic wand. This ingenious system is highly accurate and affordable. Two different units (which use the same operating principles are available: OXY-MINI and OXY-MICRO.
APP NOTE: Using a Microscope with a Stereotaxic Frame
You can use the PZMIV stereo microscope with a stereotaxic frame as shown in the image below. This setup shows a PZMIV-BS. The U-frame Base Plate (502045) is shown, but most stereotaxic frames can be used in this way. Choose a stereo microscope objective that allows you plenty of room to work. For example, the 0.5X objective has 187mm working distance, or the 0.32X objective has 296mm working distance. You could also add a Z-LITE-Z186 illuminator. If necessary, use a 5 to 10 lb.counter weight on the boom stand base to prevent the microscope from tipping.
Biosensor Specifications
WPI offers a range of biosensors for monitoring nitric oxide, hydrogen peroxide, oxygen and hydrogen sulfide. Specifications for these sensors are detailed below.
DLC Coating Multiplies Useable Life of Surgical Instruments
When applied to surgical instruments, Diamond-Like Carbon coating dramatically increases the life of the instrument. Because DLC-coated surgical instruments are incredibly durable and resistant to wear from chemicals, moisture and atmospheric conditions, they have a much greater useful lifespan. According to the manufacturer, pure DLC coatings as thin a 2-3μm can increase the lifespan of a pair of Vannas scissors more than 100 times that of its uncoated counterpart.
Compare Dri-Ref Reference Electrodes
Dri-Ref™ reference electrodes were developed by WPI to have extremely low electrolyte leakage properties, hence the name “Dri-Ref.” In addition to this key feature, these electrodes exhibit stable and reproducible potential and low resistance. Stored in KCl when not in use, they have a long life expectancy. Low leakage is achieved by using KONBO™, a product combining modern ceramic and conductive polymer technology, as the liquid junction. Electrode resistance is low, an important consideration when making low-noise measurements.
APP NOTE: Microinjection Setup 101
When it comes to setting up microinjection systems, the options appear endless. The pictures below give some broad suggestions on how you might set up your own system. Keep in mind that many parts are interchangeable depending on your needs or preferences.
Ag/AgCl Half Cells
WPI's silver-silver chloride half cells are new, improved sintered pellets with lower resistance and high strength. They are stable and well-balanced in the presence of current. These small and inexpensive half-cells are easy to work with as bath electrodes.
Microscope Basics
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 image on a PC or TV or to take still images.) The answers to these questions help you determine the required working distance, level of magnification, type of mounting stand and hardware required.
Metal Microelectrodes Basics
Superior microelectrodes for outstanding extracellular recording — tungsten, iridium, platinum-iridium, and Elgiloy®
Metal Microelectrode Selection Guide
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.
14011 Luer Valve Assortment Kit Pictures
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.
What's the Difference Between a 3-way and 4-way Stopcock?
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.
Variety of Pre-pulled Micropipettes Available
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.
Metal Electrodes Selection Guide for Assortments and Concentric
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.
Metal Electrode Selection Guide for Profile C
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 of the electrode unfavorably.