Introducing EVOM™ Auto ElectroZ: Beyond TEER to Advanced Cellular Barrier Analysis

EVOM™ Auto ElectroZ

A new dimension in barrier function research with automated TEER and electrochemical impedance spectroscopy on a single platform.

For decades, researchers have relied on WPI's EVOM™ technology to measure transepithelial/endothelial electrical resistance (TEER), a trusted indicator of cellular barrier integrity. With thousands of citations in peer-reviewed literature, EVOM™ instruments have become an established part of research involving epithelial and endothelial barriers, drug discovery, and disease modeling.

Now, WPI is advancing that technology further.

Introducing EVOM™ Auto ElectroZ, which brings electrochemical impedance spectroscopy (EIS) to WPI's automated, high-throughput TEER platform. By combining traditional TEER measurement with multi-frequency impedance analysis, EVOM™ Auto ElectroZ provides a more comprehensive understanding of cellular barrier integrity, morphology, maturation, and function.

And, it does so without requiring researchers to abandon their existing cell culture protocols or invest in an entirely separate EIS instrument.

Two Measurement Modes. One Powerful Platform.

One of the most significant advantages of EVOM™ Auto ElectroZ is its versatility. With interchangeable electrode arrays, researchers can switch between two distinct measurement modes using the same instrument.

Classic Mode: Trusted TEER Measurement

Classic mode provides the familiar, reliable TEER measurements that researchers have used for decades. Using a 12.5 Hz alternating current, it measures electrical resistance across epithelial or endothelial cell layers, providing a quick, non-destructive assessment of barrier integrity.

As tight junctions develop and mature, TEER values typically increase, reflecting the formation of a more restrictive barrier. Classic mode is ideal for routine barrier assessment, quality control, and experiments requiring straightforward TEER measurements.

ElectroZ Mode: Advanced EIS Analysis

ElectroZ (EZ) mode expands the analysis beyond a single frequency. By measuring impedance across a frequency range of 2 Hz to 100 kHz, ElectroZ captures both resistive and capacitive properties of living cell layers.

These measurements reveal changes in cellular behavior that traditional TEER alone cannot fully characterize, including cell growth, maturation, membrane properties, and polarization.

Switching between Classic and ElectroZ modes is as simple as swapping electrode arrays. Automatic electrode head detection configures the instrument and software for the selected array, minimizing setup time and simplifying operation.

Five Measurements for Deeper Cellular Insights

Traditional TEER measurements provide valuable information about barrier integrity, but that represents only part of the picture. ElectroZ adds multiple parameters that help researchers understand how cells develop, mature, and respond to experimental conditions and drug treatments.

TEER Cellular: Cell Layer Resistance Without a Separate Blank

Conventional TEER workflows require a blank measurement to account for resistance contributed by the culture insert and surrounding solution. ElectroZ uses multi-frequency impedance analysis to distinguish cell layer resistance from background resistance automatically.

The result is TEER Cellular, an area-normalized measurement of the cell layer's resistance without the need for a separate blank sample or manual background subtraction. This simplifies workflows, saves time, and reduces opportunities for handling errors.

Consider a cell layer grown on a biodegradable scaffold. As the scaffold degrades over time, manually determining and subtracting the appropriate blank measurement at each time point can be challenging and prone to error. EVOM™ Auto ElectroZ simplifies this process by automatically detecting and subtracting the blank at any time point, even as the scaffold degrades.

TEER Total: Complete Electrical Resistance

TEER Total measures the combined resistance of the cell layer and solution, normalized to the well area. Together, TEER Total and TEER Cellular provide a clearer understanding of the electrical characteristics of the culture system.

Transepithelial Capacitance (TEC): Insights Beyond Barrier Integrity

While TEER measures resistance, TEC characterizes the capacitive properties of the cell membrane. Changes in capacitance can provide insights into cellular growth, morphology, and maturation, including the development of specialized structures such as microvilli and cilia. This additional information helps researchers distinguish changes in barrier resistance from changes in cellular structure.

Tau Ratio: Understanding Cellular Polarization

The Tau Ratio compares the time constants of the apical and basolateral cell membranes, providing an indicator of cellular polarization. This is particularly valuable when studying epithelial and endothelial models in which the development of distinct apical and basolateral membrane properties is important for physiological function.

Goodness of Fit: Confidence in the Analysis

ElectroZ evaluates and shows how closely the acquired impedance data fits the selected equivalent cell circuit model. Goodness of Fit provides researchers with an important measure of model agreement, helping them assess the quality of their EIS analysis and identify measurements that may require closer examination.

Together, these five outputs provide a more comprehensive electrical characterization of cellular barriers than traditional single-frequency TEER measurement alone.


Advanced EIS Without Specialized Cell Culture Plates

Not all impedance measurement systems use the same approach. Some competing technologies rely on proprietary cultureware with electrodes embedded directly into the growth surface. These configurations can require researchers to change or modify established culture protocols and purchase specialized consumables.

EVOM™ Auto ElectroZ takes a different approach. Using WPI's established pin-style electrode technology, ElectroZ measures cells grown on compatible, commercially available 24- and 96-well permeable membrane culture inserts. There is no requirement to grow cells directly on embedded electrodes or microelectrode arrays. This flexibility offers several important advantages:

  • Preserve established protocols. Continue using familiar culture formats without redesigning experiments around proprietary electrode plates.
  • Maintain apical and basolateral access. Support polarized cell cultures and physiologically relevant models requiring exposure on both sides of the cell layer.
  • Accommodate complex models. Study epithelial and endothelial barriers, co-cultures, blood-brain barrier models, gastrointestinal tissues, and engineered tissue systems.
  • Extend the value of every sample. Use the same cultures for additional analyses, including permeability assays and immunocytochemistry.

For laboratories working with carefully optimized cell culture systems, the ability to add EIS analysis without fundamentally changing the experimental model is a significant practical advantage.

Follow Cellular Development Throughout an Experiment

Cellular barriers are dynamic. Cells attach, proliferate, differentiate, form tight junctions, and respond to changes in their environment. A single TEER measurement can provide a snapshot of barrier integrity. Multi-frequency EIS adds information about how the electrical properties of the cell layer change over time.

For example, capacitance may increase as cells attach and proliferate, while resistance remains relatively low. As cells become confluent and tight junctions mature, resistance typically increases, reflecting the development of a functional barrier.

By tracking both resistive and capacitive properties, ElectroZ helps researchers characterize these different stages of cellular development. Because measurements are non-destructive, researchers can monitor living cells before treatment, during an experiment, and after exposure to drugs, toxins, or environmental conditions. This makes ElectroZ particularly useful for drug discovery, disease modeling, barrier maturation studies, and quality control of cellular models.

Automation That Does More Than Save Time

EVOM™ Auto was designed to simplify high-throughput TEER measurement. ElectroZ extends that efficiency to advanced EIS analysis. Interchangeable electrode arrays accommodate compatible 24- and 96-well plates, while automated, column-by-column measurement reduces repetitive manual handling.

Researchers can configure scheduled measurements at defined intervals, allowing the instrument to execute measurement cycles automatically without requiring their presence. Additional automation features help maintain consistency and protect valuable samples and equipment:

  • Automated rinsing and disinfection workflows with three rinse locations and customizable sequences help minimize cross-contamination.
  • Disposable rinse station inserts simplify solution changes between measurement cycles.
    Automatic electrode head detection streamlines setup when changing plate formats or measurement modes.
  • Crash protection and alignment detection pause measurements when an alignment issue is detected, helping prevent electrode damage and costly downtime.
  • User-defined data limits allow measurements to be flagged against established thresholds, supporting quality control and pass/fail screening.

Together, these capabilities reduce hands-on time, improve workflow consistency, and help laboratories manage larger numbers of samples efficiently.

Powerful Software for Routine and Advanced Analysis

ElectroZ accommodates researchers who need straightforward results, as well as those who want greater control over their EIS experiments. WPI-optimized frequency configurations simplify routine measurements, while advanced settings allow researchers to create custom frequency profiles or use the frequency optimizer.

The software automatically calculates key measurement parameters and provides access to Goodness of Fit information, Nyquist and Bode plots, and raw impedance data for further analysis. This combination of automated calculations and advanced analytical tools makes ElectroZ accessible for routine barrier studies while providing the flexibility required for more sophisticated research.

A New Standard for Versatility in Barrier Research

EVOM™ Auto ElectroZ represents more than an expansion of measurement capabilities. It brings together the trusted performance of WPI's TEER technology, the analytical depth of multi-frequency EIS, and the convenience of automated high-throughput operation.

Researchers can move between Classic TEER and advanced ElectroZ analysis without changing instruments, use commercially available permeable membrane culture inserts, and obtain additional insights into cellular resistance, capacitance, and polarization.

From routine barrier integrity measurements to complex studies of cellular development and treatment response, EVOM™ Auto ElectroZ gives researchers more information from their existing cell culture models while simplifying the path from measurement to discovery.

WPI's new ElectroZ, aptly abbreviated EZ (easy), simplifies complex EIS measurements with intuitive software, streamlined workflows, and easy-to-interpret data. Go beyond TEER. Discover what ElectroZ can reveal about your cellular barriers.