KCS

Droplet microfluidics (DMF) has been developed and used as digital assays for accurate and absolute quantification of biological markers such as viruses, bacteria and nucleic acids. Currently, representative droplets analysis approaches include one-dimensional channel detection and two-dimensional area detection. However, these approaches have the disadvantage of expensive optic system and end-point detection, and require a high-throughput and rapid assay time. To avoid complex and expensive optic system as a detector, CMOS image sensor and smartphones have been integrated with DMF to analysis droplets. Here, we introduce a droplets analysis approach for multiplexing, absolute quantification and high-throughput. In this approach, DMF was integrated with wide-field imaging system (WIS) for the accurate and precise digital quantification of droplets within a single image. To setup the WIS, 100 mm macro lens and 50.6-megapixel CMOS image sensor were used to image droplets, and droplet images were identified with MATLAB-based homemade software that simultaneously analyzes eight individual colors for multiplexed, real-time monitoring and absolute quantification. Using this platform, it can be used for identification of each eight different targets (colors) and sensitivity was characterized as low as 0.01%. The WIS allowed imaging area from a minimum of 11.48 cm2 to a maximum of 201.84 cm2 and theoretical number of droplets, that can be analyzed, were calculated from 5.84x105 to 1.03x107 droplets when droplets are generated at 50 μm in a diameter. This platform technology will provide a tool for high-throughput, absolute and real-time quantification of droplets that can be used as a tool such as high-throughput digital PCR and digital ELISA for accurate diagnostics.