On-chip real-time detection and quantification of reactive oxygen species in MCF-7 cells through an in-house built fluorescence microscope

Reactive oxygen species (ROS) are formed by several different reactions and play a major role in cell cycling and as a messenger in normal cell transduction and have diverse biological effects when high in concentration. ROS may trigger DNA damage, cell mutation, inflammation, cell proliferation, and ultimately they may induce carcinogenesis. This study aims to design, fabricate, and develop a novel on-chip ROS detection based on mounted in-house built fluorescence microscope in microfluidics, which has not been reported previously. An in-house 3D printed built digital portable fluorescence type microscope for on-chip ROS detection has been developed. The combined use of the fluorescence microscope and a glass-based microfluidic chip both enabled to provide high-quality images of the living cells with ease of controlling and handling of the biological sample. As an evidence of the fluorescence microscope, breast cancer cells were loaded with 2′,7′-dichlorofluorescein diacetate (DCFDA, 50 μM) for 45 min on-chip which produces green fluorescence upon reaction with intracellular ROS. Fluorescence of the MCF-7 cells has been captured to obtain a profile of ROS generation for 1 day. LabVIEW 2019 was used along with its high-performance image analysis and IMAQ Vision tools. The viability of the cells was performed by LIVE/DEAD assay and Luna cell counter. The developed platform provides real-time monitoring and quantification of ROS. A strong linear correlation between concentrations versus fluorescence has been recorded. This result recommends that the current microfluidic chip provides an in-vitro platform for the assessment of cell cycle progression and evaluation of the variety of drugs.