Microfluidic Single-Cell Monitoring Versus Microplate Bulk-Cell Measurement

This study compares two methods for measuring cell changes: a microfluidic chip single-cell monitoring and a microplate bulk-cell measurement. As intracellular calcium ion concentration ([Ca2+]i) plays a critical role in various cellular functions and biochemical processes, measurements of [Ca2+]i may be used to compare the two methods. The microfluidic approach allows real-time monitoring of individual cells, utilizing the fluorescence emitted from calcium-Fluo 4 chelate, while the microplate method offers bulk analysis of approximately 10,000 cells per well in a 96-well microplate. We have demonstrated that the single-cell method provides insights into [Ca2+]i dynamics with low reagent consumption and rapid analysis, whereas the microplate method enables comprehensive bulk measurements when isolation of single cells is difficult. By integrating both techniques, we aim to complement measurements on both single-cell and population levels, especially when cell availability is an issue. For the cellular process, we specifically investigated the increase in [Ca2+]i following histamine receptor activation, in ACE2-enriched A549 and wild-type A549 cells. In our findings, both approaches yielded consistent calcium-signaling patterns, that wild-type A549 cells exhibited stronger histamine-induced calcium responses than ACE2-enriched cells, and that the two methods complement each other—single-cell assays providing temporal and low-reagent analysis, while bulk assays provide high-throughput, population-level averages.