A droplet-to-digital (D2D) microfluidic device for single cell assays.

Area of Science:

• Biotechnology
• Microfluidics
• Cell Biology

Background:

• Multi-step biochemical assays require precise control over droplet manipulation and analysis.
• Existing microfluidic platforms have limitations in integrating diverse functionalities for complex assays.

Purpose of the Study:

• To develop and validate a hybrid droplet-to-digital microfluidic (D2D) platform for automated multi-step biochemical assays.
• To assess the utility of the D2D platform for ionic liquid (IL) toxicity screening on yeast cell growth and ethanol production.

Main Methods:

• Integration of droplet-in-channel microfluidics for single-cell encapsulation with digital microfluidics (DMF) for droplet manipulation.
• Automated reagent addition, parallel cell culturing using a Peltier element, and impedance sensing for flow control.
• Evaluation of yeast response to varying IL types and concentrations, with analysis of growth kinetics and ethanol production.

Main Results:

• The D2D platform successfully performed parallel single-cell culturing and analysis for IL toxicity screening.
• Increased IL concentration negatively impacted yeast biomass and ethanol production, with [C2mim][OAc] showing significant inhibitory effects.
• Growth curve data from the D2D platform correlated with conventional microtiter well assays, validating the system's performance.

Conclusions:

• The developed D2D platform offers a versatile and automated solution for complex, multi-step biochemical assays.
• This technology holds promise for applications in drug screening, digital PCR, immunoassays, and other cell-based assays.
• The D2D platform provides a robust method for evaluating the effects of various compounds on cellular processes.