Evaluation of Trans-epithelial Electrical Resistance by Removal and Replenishment of Extracellular Ca²⁺

Abstract

We developed a bi-channel microfluidic device integrated with a four-probe electrode system to measure the trans-epithelial electrical resistance (TEER). Time course of TEER was monitored when the extracellular Ca²⁺ was removed and replenished both from the upper and lower channels. We showed that tight junctions were disrupted rapidly once Ca²⁺ was removed from the basal side. However, when Ca²⁺ was removed from the apical side such disruption progressed slowly. Upon replenishing Ca²⁺ content at the basal side the TEER recovery pace was also faster than the case of replenishing it at the apical side. We conclude that cell polarity needs to be taken into account during the process of Ca²⁺ removal/replacement in explaining the dynamics of tight junction disruption/recovery. These results indicate that our approach can be utilized in detecting cell polarity in real time and low invasion.