An integrated electrophysiological and optical approach for ion channel study in a microfluidic system enabling intra- and extra-cellular solution exchange

The planar patch-clamp technique has revolutionized ion channel study by increasing throughput and minimizing sophisticated operation. Nevertheless, the system design is often focused toward a particular objective, which sometimes limits the range of information output. Here, we present an integrated electrophysiological and optical approach for ion channel study in a microfluidic system allowing multi-content detection. Multiple fluidic injections enable both intra- and extracellular solution exchange to facilitate the study of the ion channel in a microfluidic chip with high-yield seal formation. Whole-cell and single cell recordings were validated for various cell lines, i.e. endogenous channels of HIT-T15, CHO-K1, HEK-293T, and RIN-m5f cells. Long-term recording of temporal fluorescent changes on a trapped RIN-m5F cell shows the ability of extracellular solution exchange and simultaneous optical observation. The integrated microdevice system serves as a practical tool for high-quality and multi-content ion channel electrophysiological study.