VIDEO: Which EVOM™ Electrode is Right for Your Application?

WPI’s EVOM™ Manual is the gold standard for delivering stable and repeatable Trans Epithelial Electrical Resistance (TEER) measurements. The EVOM™ Manual is the newest TEER meter. It qualitatively measures cell monolayer health and quantitatively measures cell confluence by determining an increase or a plateau in tissue resistance detected using our innovative EVOM™ technology. WPI’s state of the art EVOM™ technology provides you with real-time, valuable feedback during experimental measurements.

VIDEO: How to Replace the STX4 Electrode Blades

The new STX4 electrode works with the EVOM3, and the blades are replaceable. EVOM3 is used for making TEER (TER) Measurements in cell culture plates. Here's a quick tutorial to show you how to replace the blades.

Organ-on-Chip, TEER, and New Drug Development

The process of drug discovery and development is extremely slow and expensive. Regulatory authorities, such as US FDA need animal models to test absorption, distribution, metabolism, and excretion (ADME) which estimates safety and effectiveness of a drug. 

VIDEO: Researcher's Review of the EVOM3

The EVOM is a special kind of voltmeter for measuring electrical properties across a layer of cells in culture or a biological membrane. It is the most commonly used commercial system for measuring across a layer of cultured cells. We are measuring TEER (TER) - Transepithelial Electrical Resistance. The EVOM3 allows us to zoom in and measure either resistance or voltage across these membranes or cells in culture.

VIDEO: What I Like About the EVOM Line

The EVOM is a special kind of voltmeter for measuring electrical properties across a layer of cells in culture or a biological membrane. Here's a few things I like about the new EVOM3.

VIDEO: Researcher Compares EVOM3 with an Ussing Chamber

An Ussing Chamber is used when performing barrier studies across an excised epithelial tissue. Similar measurements can be made in well plates using an EVOM series TEER Measurement Meter, which is used for epithelial tissue that is grown to confluence in a cell culture well. While EVOM measurements are only qualitative, your throughput is much greater with an EVOM3. The EVOMs are portable and much more economical than an Ussing Chamber. Here Ben Dubansky, PhD explains the differences between EVOMs and Ussing chambers.

VIDEO: 7 Reasons to Love the New EVOM3 for TEER Measurement

The NEW EVOM3 Epithelial Volt/Ohm Meter delivers improved workflow efficiency, increased stability and more repeatable measurements than traditional Trans Epithelial Electrical Resistance (TEER) meters. Here are seven things you will love about the new EVOM3.






Significance of Transepithelial/ Transendothelial Electrical Resistance (TEER) Measurement in Lung In vitro Models 

Epithelial and endothelial cells are known for their barrier function like selective permeability. Lung tissue is comprised of epithelial cellular layers, residing adjacent to endothelial layers and allowing exchange of oxygen and carbon dioxide between lung and blood. Currently, the biomedical research community’s major focus area is to understand the details of the infection caused by this novel coronavirus (2019-nCoV) or by similar viruses. This new virus can disrupt the lung’s normal cleaning ability to get rid of foreign particles in the lung, and the selective permeability or barrier function of the lung may become severely impaired. The adverse physiological effect may be sustained once the inflammatory cascade is initiated.

7 Reasons to Love the NEW EndOhm Chambers

EndOhm chambers are designed for making accurate TEER measurement of epithelial and endothelial cell cultures. Thedesignkeeps the top and bottom electrodes at a fixed gap and maintains the sample (cell culture insert) in a centered position inside. This designminimizes the variability associated with electrode positioning and gap, making EndOhm chambers more accurate and capable of generatingreproducible results.WPI made some recent upgrades to theEndOhm chambers.

How to Set the Gap on your WPI EndOhm Chambers

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.

Resurfacing Electrodes in a WPI EndOhm Chamber

WPI EndOhm chambers are used with WPI's EVOM2 meter for making TEER (transepithelial electrical resistance) measurements. After heavy use your background resistance measurement may start to rise. Your electrodes may need to be resurfaced to remove buildup of proteins, sugars and biological materials. Here Subhra demonstrates how to clean and resurface your EndOhm chambers.

Choosing an EndOhm Chamber Compatible with your Cell Culture Inserts

WPI's EndOhm chambers are used with WPI's EVOM2 meter to measure TEER (transepithelial electrical resistance) in cell culture inserts. Three chamber sizes are available for 6-well plates, 12-well plates and 24-well plates. Here Subhra demonstrates how to choose an EndOhm chamber to match the cell culture inserts you are using.

FAQ: Troubleshooting Unstable Resistance Readings from an ENDOHM

One of our frequently asked questions (FAQs) concerns TEER measurements with an EndOhm. If the resistance readings from your ENDOHM don't stabilize, you may need to do some troubleshooting.

Endohm Maintenance for Long Life

The EndOhm series of chambers, when used with WPI’s EVOM2 resistance meter or the Millicell ERS, are designed to provide reproducible and accurate resistance measurements of endothelial tissue in culture cups. Resistance values obtained with the EndOhm are consistent with those obtained using a well-designed Ussing Chamber.

Monitor the Growth of Epithelial Cells in Vitro Manually

Are you ready to perform experiments involving a cultured cell monolayer? If your monolayer has not reached confluence, you may have holes or gaps in the monolayer that would prevent collection of valid experimental data. When confluence is reached, the electrical resistance across the monolayer peaks and then plateaus. The EVOM2 meter was designed specifically for this application.

The EVOM2 is the ideal meter for use when you are making manual TEER measurements on small batches of cell cultures and do not require a high throughput system.

FAQs about TEER Measurement

Here are some frequently asked questions (FAQ) about TEER measurement using an EVOM2.

Recording TEER Measurements from an EVOM2

The EVOM2 is the classic, hand-held instrument for making Trans Epithelial Electrical Resistance (TEER) measurements. The REMS system adds a robot and data recording for automated TEER measurements. There may be times when you don't have a robot, but would still like to have the data recording capabilities of the REMS system. With a little ingenuity, you can do just that. Here, we will show you how you can add data recording to your standard EVOM2.

STX100 Electrodes TEER Measurement

With the development of a High Throughput Screening (HTS) protocol for faster drug discovery, a new line of cell culture filter plates have been introduced by several major cell culture insert manufacturers. These HTS plates normally have either 24 or 96 individual cell culture inserts "bonded" together as one plate so that it can be handled by a robot apparatus. In response to these developments, WPI has developed an automatic REMS system and a manual electrode, STX100, for TEER measurements using HTS plates.

TEER Measurement in Individual Endothelial Cell Cultures Cups

WPI's EndOhm chambers were designed for making TEER measurement of endothelial cell cultures in individual cups. The EndOhm chambers feature:

Compatible with EVOM² 
Improved accuracy of 1-2Ω
Accommodates 6mm, 12mm, 24mm cups and Costar Snapwell cup
Sterilized with EtO, alcohol or a bactericide

TEER Research: WPI's Manual and Robotic Systems

Transepithelial Electrical Resistance TEER measurements is the most convenient, reliable and non-destructive method for evaluating and monitoring the growth of epithelial tissue cultures in vitro. The confluence of the cellular monolayer is quickly determined by a sharp increase in TEER. TEER measurement technology, which was first introduced by WPI in the mid-1980's, has since been perfected and expanded to include a range of TEER related manual and automatic instrumentation, including:

EVOM² - Manual TEER measurement of epithelial cells in 24- and 96-well plates
REMS AutoSampler - Automated system for High Throughput Screening (HTS)

EVOM or Volt Meter: Defining the Difference

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:

How To Test Your EVOM2 Meter

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.

EVOM2-How to Equilibrate Your STX2

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.