Optical Detection Methods for High-Throughput Fluorescent Droplet Microflow Cytometry

Abstract

High-throughput microflow cytometry has become a focal point of research in recent years. In particular, droplet microflow cytometry (DMFC) enables the analysis of cells reacting to different stimuli in chemical isolation due to each droplet acting as an isolated microreactor. Furthermore, at high flow rates, the droplets allow massive parallelization, further increasing the throughput of droplets. However, this novel methodology poses unique challenges related to commonly used fluorometry and fluorescent microscopy techniques. We review the optical sensor technology and light sources applicable to DMFC, as well as analyze the challenges and advantages of each option, primarily focusing on electronics. An analysis of low-cost and/or sufficiently compact systems that can be incorporated into portable devices is also presented.

Real-Time Tracking of Individual Droplets in Multiphase Microfluidics

“…Overall, thanks to the aforementioned advantages LEDs are currently the most used technology for dynamic detection of the droplets in micro-and millifluific setups. Fluorescent microscopy with the integrated Charge Coupled Device (CCD) sensors and CMOS sensors are still actively employed to offer spatial monitoring of the droplets-fluorescence over time [18] (Figure 1e). This has high relevance for the realization of the droplet-based digital Polymerase Chain Reactions (PCR) and next generation sequencing for monitoring of e.g.…”

“…Figure 1. Complete system for (a) droplet processing, (b) generation, (c) storage, (d) sorting, and (e) image analysis.Adapted with permission from refs [18,19]…”

Particle Counting Methods Based on Microfluidic Devices

“…The principle of the fluorescence counter is shown in Figure 2 a. The fluorescence counter typically consists of an excitation light source, objective lenses, dichroic mirrors, a microfluidic sample platform, a photodetector, and a data acquisition and processing unit [ 23 , 24 ]. As fluorescent particles pass through the optical window, they are excited by an appropriate wavelength of light, and the emitted light is detected by a photodiode and converted to electric signals [ 25 ].…”

“…Recent research has shown a growing interest in the development of high-throughput microfluidic counters [ 24 ]. To this end, Li et al [ 31 ] presented an optical flow cytometer (OFCM) for single-cell phenotype counting.…”

Design of Cyber Bio-analytical Physical Systems: Formal methods, architectures, and multi-system interaction strategies

“…The primary factors driving this increased demand are the need to advance drug development, analysis, testing, and rapid diagnostic methods [1,2,3]. However, there are several challenges associated with achieving this automation, and the problem complexity is well-defined in our previous works [4,5] i.e. automation of chip design, sensor technology, light source, and fabrication processes.…”