VIDEO: EVOM™ Auto, Introducing the Experiment Screen

The EVOM™ Auto automates measurements of TEER in epithelial or endothelial monolayers cultured on high throughput screening 96-well plates utilizing our innovative EVOM™ technology, qualitatively measuring cell monolayer health and quantitatively measuring cell confluence by determining an increase or a plateau in tissue resistance.

The video below shows details the features and functions of the Experiment window on the EVOM™ Auto:

APP NOTE: A Comparative Time Study of the EVOM™ Auto versus the REMS

World Precision Instruments' (WPI) legacy Robotic Epithelial Measurement System (REMS) and the new advanced, upgraded version of REMS, EVOM™ Auto, are high-throughput, automated transepithelial/transendothelial electrical resistance (TEER) measurement systems. These robotic systems, combined with EVOM™ technology, expedite TEER measurements.

 

VIDEO: How to Set up the EVOM Auto TEER Measurement System

Have you got the new EVOM Auto TEER Measurement System for 96-well HTS plates? This short videos shows how easy it is to setup.

VIDEO: Unboxing the EVOM™ Manual TEER meter

EVOM™ Manual is WPI's newest instrument to measure Trans Epithelial Electrical Resistance (TEER). Let's look at what comes with the system and how easy it is to setup.

Common Applications for EVOM Manual

WPI's EVOM system is popular in the research community, both in academia and in industry, and it is commonly used for the evaluation of mammalian cellular health by measuring transepithelial/transendothelial electrical resistance (TEER or TER) of cellular layers. 

EVOM™ Manual is powered by the same EVOM™ technology as older EVOM models (EVOMX, EVOM, EVOM2 and EVOM3). It has advanced features for performing experiments more easily. With the new touchscreen display you can now store data as Microsoft® Excel files on a USB flash drive. Just remove the flash drive with all your recorded data from the EVOM™ Manual and plug it into a computer to access and plot your data. It is as simple as it sounds.

VIDEO: Understanding the EVOM™ Manual's Main Display Page

WPI’s EVOM™ Manual is the gold standard for delivering stable and repeatable Trans Epithelial Electrical Resistance (TEER) measurements. The EVOM™ Manual 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. The main display window has lots of information. Here’s a quick overview. You can download the infographic for a handy reference.

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: 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.

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 Select Electrodes For Making TEER Measurements

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).

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.

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 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)

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.

 

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.