A Low-Cost and Customizable TEER Meter for the Measurements of Cellular Barrier Integrity

A low-cost and translational TEER (trans-endothelial/epithelial electric resistance) meter was designed, fabricated, validated, and applied in this paper. TEER is a critical tool to quantitate the integrity of biological barriers. Commercially available TEER meters are expensive (thousands of dollars) with low customization capability. Using Arduino, an open-source hardware and program that are used to control electronics, we fabricated the TEER meter that costs ~$50 to purchase the parts and 2 hours to be constructed. Robust characterization and validation shows that the meter can accurately measure TEER values between 132 and 82,500 Ω·cm² with <3% errors, which covers the reported TEER ranges based on a literature study we conducted. The temporal resolution, the measurement duration, and the electrode configurations of meter are also customizable. We successfully applied the meter to measure TEERs of endothelial cell monolayers, finding that cells treated with histamine have lower TEER values compared to untreated cells (793.4 ± 190.5 Ω·cm² vs. 3027.5 ± 664.4 Ω∙cm²; p < 0.001), which is consistent with literature results. We further validated the TEER measurement by showing that histamine increased the intercellular gap from 2.34 ± 0.12 µm to 5.49 ± 0.17 µm, causing leakier endothelial barriers and thus lower TEERs. In conclusion, we report for the first time a low-cost Arduino-based TEER meter capable of accurately measuring TEERs in the relevant range. We also include detailed tutorials in the supplementary information to promote the translation of the technology.