Integrated Optical Tweezers and Microfluidic System for Monitoring Cellular Response

Single-cell analytics plays a vital role in monitoring cellular processes which cannot be accurately observed with ensemble data. Optical Tweezers and Microfluidic devices provide this capability as shown by several previous studies [1], [2]. Here we present an integrated optical tweezers and microfluidics system with a fluorescence module which allows for the monitoring of the morphology and metabolic activity of single yeast cells (Saccharomyoces cerevisiae). The microfluidic chip used was a commercially available 3in1 chip which producing laminar flow inside the chamber to generate two distinct and separate environments. Using this system, yeast cells were exposed to two different bioeffectors which induced cellular stress responses when moving trapped cells between these environments. Osmotic stress is a well-known phenomenon where a change in salinity levels around the cell alters the cell volume due to a build up of osmotic pressure at the membrane interface [3]. Figure (1a) shows the average normalised cell area of a sample of single cells (N=13) periodically exposed to increased salinity levels.