WPI Blog

Nitric oxide (NO) is an essential signaling molecule and is known to play a significant role in a multitude of physiological systems including the central nervous system (CNS), the cardiovascular system, the gastrointestinal tract, the immune system, and the renal system. ^1-5 However, being highly reactive, detection and quantification of NO is very difficult.^6,7 It requires a sensor that is sensitive, selective to NO, and easy to calibrate.

Microinjection is the process of transferring genetic materials into a living cell using glass micropipettes or metal microinjection needles. Glass micropipettes can be of various sizes with tip diameters ranging from 0.1 to 10 µm. DNA or RNA is injected directly into the cell’s nucleus. Microinjection has been successfully used with large frog eggs, mammalian cells, mammalian embryos, plants and tissues. Microinjection has been expensive, can be a slow process and requires skilled personnel, but new technologies are making it even more reliable, repeatable and affordable.

All chemical reagents should be of at least ACS-Grade, preferably HPLC-Grade. This procedure involves the use of caustic and flammable reagents. Consult the manufacturer’s MSDS for necessary safety precautions.

Black coated surgical instruments are not only visually more attractive than the stainless-steel ones, there are several other benefits as provided below.

Whether you are working with your surgical instruments under bright lights or using a microscope, non-reflective black surgical instruments offer a distinct advantage. The titanium coating not only hardens and protects the cutting edge, but it also minimizes reflection from the surface of your instruments while you are working. They are corrosion resistant and biocompatible. 

MICRO-ePORE™ pinpoint cell penetrator is a simple and versatile system that can be used to facilitate microinjection of a diverse array of compounds and biomolecules into oocytes and pre-implantation stage mammalian embryos. Patent pending Flutter Electrode Technology assists in small, clean, precise membrane penetration without tearing or damaging the membrane. It results in substantially increased viability of embryos.

The new WPI MICRO-ePORE™ Pinpoint Cell Penetrator is a simple and versatile system that can be used for efficient microinjection of a diverse array of compounds and biomolecules into oocytes and pre-implantation stage mammalian embryos. Patent pending Flutter Electrode Technology assists in small, clean, precise membrane penetration without tearing or damaging the membrane. Here Gabe sets up the system and connects all the components.

For intracellular dual or differential studies, WPI's Duo773 has separate negative capacity controls and built-in active filtering that allows the precise balancing of time constants for artifact-free differential measurement. It comes complete with two probe headstages, 10¹⁵Ω and 10¹¹Ω probes to monitor signals from ion-specific micro-electrodes as well as KCl-filled electrodes. Jim shows you how to safely unpack and properly setup your new Duo773.

Here are some frequently asked questions (FAQ) about Metal Microelectrodes. Click on the question to reveal the answer.

Prior to sterilizing surgical instruments, it is a good idea to make sure you have cleaned them to remove blood, tissue and all other organic material.  If soiled materials dries or is baked onto the instruments, it will interfere with microbial inaction and can compromise the sterilization process.

WPI EndOhm chambers are used with WPI's EVOM2 meter for making TEER (transepithelial electrical resistance) measurements. Each EndOhm chamber comes with a "spacer" disk for calibrating the gap between the two chamber electrodes. A consistent gap ensures reliable measurements. Here Subhra shows how to calibrate your chambers.

The Butantan Institute, an agency linked to the State Department of Health of São Paulo and one of the largest biomedical research centers in the world, held the 4th edition of the Zebrafish Creation and Management university extension course in December where they exhibited WPI's Zebrafish Microinjection System.

Transepithelial electrical resistance (TEER), also referred as the transepithelial resistance (TER) is used to monitor cellular health. TEER is comprised of measurements of the transcellular pathway (i.e., resistance due to an individual cell) and paracellular pathway (i.e., resistance due to the formation of the cellular junctions). TEER is commonly used to monitor cellular confluence. TEER values can indicate changes in the cellular monolayer permeability, showing the monolayer barrier function of cells such as, endothelial (brain microvessel) and epithelial (alveolar, kidney, and intestinal) cells. High TEER values generally reflect tighter cellular monolayers or cellular junctions (Lewis 1996, Matter and Balda 2003, Denker and Sabath 2011). A few major benefits of WPI TEER measurement systems are described below. The TEER values (electrophysiological analysis) can be combined with other analysis methods to further understand a biological phenomenon. For example, a decrease in the TEER value can indicate increased monolayer permeability which can be further confirmed by an assay using a tracer molecule (fluorescein-dextran).

Jonas de Jesus, from WPI Brasil visit the winner of a contest to name a mascot for the Zebrafish Network. Jonas presented the winner with a surgical kit for zebrafish research.

One's imagination is the limit with practical uses of WPI's Liquid Wavelength Capillary Cells(LWCC), also referred to in the fiber optic spectroscopy community as a Long Pathlength Flow Cell. This fiber optic sampling accessory for absorbance measurements combines increased optical pathlengths with small sample volumes making them ideal for water analysis such as CDOM.

When you need to quickly take minimally invasive, small samples, the biopsy punch is an easy choice. The biopsy punch is a hand held, pencil-shaped instrument with a slender, pencil-like body. It is lightweight with a hollow, circular, stainless steel, cutting tip.

When you are selecting surgical instruments for a procedure, here are a few key points to consider

• What procedure are you performing? Published research papers usually indicate which instruments other researchers have used for similar procedures. The correct surgical instrument for a particular procedure makes a difference on the outcome of that technique.
• What is the size of your subject? An instrument that is perfect for a 200­–300 g rat (about 22–25 cm long) may not be the best choice for a neo-natal mouse of about 15 g (about 1–2.5 cm long).
• How often will the instrument be used? If you perform more than 100 cuts per day, a pair of titanium scissors or a pair of scissors with tungsten carbide inserts would be worth considering. They stay sharp longer.

In this video you'll see how to replace the gasket in a >Nanoliter2010. 

NOTE: NANOLITER2010 was replaced by the NANOLITER2020

The use of fluorescent probes in cell physiology has emerged as indispensable tool in the analysis of cell functioning over recent years. The physics underlying fluorescence is illustrated by the electronic-state diagram (so-called Jablonski diagram, see Fig. 1), showing the three-stage process to create the fluorescent signal (Excitation - Excited/State Lifetime - Fluorescence Emission) in a fluorophore/indicator and simplified described below.

Absorption of light correlates to the energy of a photon that is taken-up by electrons of the substance atom. The electromagnetic energy is transformed into internal energy of the absorbent substance. The absorbance of a substance quantifies how much of the incident light is absorbed by it (instead of being reflected or refracted). Precise measurements of the absorbance at many wavelengths allow the identification of a substance via absorption spectroscopy, where a sample is illuminated from one side, and the intensity of the light that exits from the sample in every direction is measured (see Fig. 1). A few examples of absorption are ultraviolet–visible (UV-Vis) spectroscopy or infrared (IR) spectroscopy.