Microfluidic assay-based optical measurement techniques for cell analysis: A review of recent progress

Since the early 2000s, microfluidic cell culture systems have attracted significant attention as a promising alternative to conventional cell culture methods and the importance of designing an efficient detection system to analyze cell behavior on a chip in real time is raised. For this reason, various measurement techniques for microfluidic devices have been developed with the development of microfluidic assays for high-throughput screening and mimicking of in vivo conditions. In this review, we discuss optical measurement techniques for microfluidic assays. First of all, the recent development of fluorescence- and absorbance-based optical measurement systems is described. Next, advanced optical detection systems are introduced with respect to three emphases: 1) optimization for long-term, real-time, and in situ measurements; 2) performance improvements; and 3) multimodal analysis conjugations. Moreover, we explore presents future prospects for the establishment of optical detection systems following the development of complex, multi-dimensional microfluidic cell culture assays to mimic in vivo tissue, organ, and human systems.