Adjacent cells of both epithelial and endothelial cells are connected to each other via intercellular junction called tight junction that regulates the diffusion of molecules and ions between the apical and basolateral side of the body. Although we demonstrated the use of our add-on device on EVOM ® instrument only, the concept (multiplexing using digitally controlled relays) and hardware (custom data logger) presented here can be applied to more advanced TEER instruments to improve the performance of those devices.Įpithelial and endothelial cells line the surface of the body. Furthermore, by monitoring temperature of the cell culture medium, we were able to detect fluctuations in TEER due to temperature change after the medium change process, and were able to correct the data offset.

To demonstrate the functionality of the device prototype, we monitored TEER in 4 transwell samples containing retinal cells (ARPE-19) for 67 h. Thus, to solve the current limitation of the EVOM ® instrument, we built an add-on device using a custom designed electronic board and a 3D printed electrode holder that allowed automated TEER measurements in multiple transwell samples. The inconsistency in electrode placement, temperature variation, and a typically large (12–24 h) time interval between measurements result in large data variabilities.

The original EVOM ® instrument is designed for measuring TEER in transwell samples manually using a pair of Ag/AgCl electrodes. This study provides design of a low-cost and open source add-on device that enhances the functionality of the popular EVOM ® instrument for transepithelial/endothelial electrical resistance (TEER) measurement.

World precision instruments evom manual