Hello, Maliheh!

In our experience at Flocel Inc., many TEER Measurement systems that are used in accordance with the Transwell do not provide consistent readings, and do not present TEER values that are anywhere close to physiological levels. In fact, we could not even get our EVOM2 to read at all sometimes, and even in the same media, it tended to randomly jump between values!

One of the key disadvantages of the Transwell (which cultures cells within a static fluid environment) is that many cell barriers require dynamic fluid shear stress to properly grow and reach confluence. This fact is represented in the resulting TEER measurements, which are markedly lower in static fluid assays. Our system, the Dynamic In Vitro Blood-Brain Barrier (DIV-BBB) overcomes this problem with its Fluid Perfusion subsystem, which provides constant pulsatile flow to the cell culture environment throughout the growth stage (the cells are seeded in the lumen of hollow fiber capillaries). Using this method, we have been able to achieve TEER values significantly higher than those experienced with Transwell applications, and much closer to in vivo levels.

This system is accompanied with our TEER Measurement Unit, which provides accurate and reproducible impedance / phase angle readings anywhere between 1-1,000 Hz (with 0.1 Hz resolution). This TEER Measurement Unit can operate on up to 4 cell culture modules at once, automatically, for an indefinite amount of time, and can automatically save the data to an excel or .csv file. No more button pushing every time you want an impedance value!

We at Flocel Inc. provide the system as a whole, as well as the Fluid Perfusion and TEER Measurement Units as standalone products (we are in the process of modifying the TEER Unit to be compatible with Transwell too). Furthermore, we offer CRO services if you wish for an experiment to be conducted in-house, which would be managed by our Scientific Director Dr. Damir Janigro. He is the creator of the DIV-BBB and a world leader in blood-brain barrier physiology.

I hope this insight helps! I encourage you to visit our ResearchGate page or website (www.flocel.com) to learn more, or contact me directly at [email protected] if you have any questions!