Digital microfluidics for time-resolved cytotoxicity studies on single non-adherent yeast cells

Abstract

Single cell analysis (SCA) has gained increased popularity for elucidating cellular heterogeneity at genomic, proteomic and cellular levels. Flow cytometry is considered as one of the most widely used techniques to characterize single cell responses; however, its inability to analyse cells with spatio-temporal resolution poses a major drawback. Here, we introduce a digital microfluidic (DMF) platform as a useful tool for conducting studies on isolated yeast cells in a high-throughput fashion. The reported system exhibits (i) a microwell array for trapping single non-adherent cells by shuttling a cell-containing droplet over the array, and allows (ii) implementation of high-throughput cytotoxicity assays with enhanced spatio-temporal resolution. The system was tested for five different concentrations of the antifungal drug Amphotericin B, and the cell responses were monitored over time by time lapse fluorescence microscopy. The DMF platform was validated by bulk experiments, which mimicked the DMF experimental design. A correlation analysis revealed that the results obtained on the DMF platform are not significantly different from those obtained in bulk; hence, the DMF platform can be used as a tool to perform SCA on non-adherent cells, with spatio-temporal resolution. In addition, no external forces, other than the physical forces generated by moving the droplet, were used to capture single cells, thereby avoiding cell damage. As such, the information on cellular behaviour during treatment could be obtained for every single cell over time making this platform noteworthy in the field of SCA.

Adhesion promoter for a multi-dielectric-layer on a digital microfluidic chip

“…4a). [28][29][30] By this way, the nonspecic adhesion between the two dielectric layers, Ta 2 O 5 and Parylene C, would be switched to a much stronger and stable chemical bonding. 4b).…”

Microfluidic Bioreactors for Cellular Microarrays

“…Therefore, the cell-array sizes are modest but the exposure of different concentrations of a compound to the same cell-array is favored by the use of an on-chip gradient generator or the same cell array could be exposed to various compounds in parallel screening channels/chambers. Digital microfluidics has been used to screen for the effect of antifungal drugs on non-adherent S. cerevisiae cells, which were patterned in a high-density microwell array [252].…”

Numerical Simulations of the Digital Microfluidic Manipulation of Single Microparticles

“…1, 2, 3 Manipulation of individual cells in small volume of liquid is of critical importance in SCA, 4 and digital microfluidics (DMF) is an emerging liquid-handling technology that enables precise control of individual picoliter liquid droplets for manipulations with isolated cells in a high-throughput fashion. 5,6,7 Currently, the design of DMF for the manipulation of individual cells is mainly based on trial-and-error method. The fundamental understanding of interactions among microparticles (including cells), droplets, and substrates is of critical importance for the design and optimization of DMF system for SCA.…”