A high throughput microfluidic platform for in vitro toxicity assays

Greg Cooksey, John Elliot (mentor), Anne Plant

Category: Biotechnology

Biochemical Sciences Division, Chemical Sciences and Technology Laboratory, Bldg 227/B264, Mailstop 8313, Telephone: x5529, gregory.cooksey@nist.gov

 

Rigorous quantitative studies that rapidly and accurately test large numbers of compounds for toxicity are a major challenge for biotechnology and pharmaceutical companies.  Large-scale biological assays often involve multi-well plate formats and expensive robotic manipulators.  Generally, these are endpoint assays that give limited, if any, information about how processes within single cells are initiated and evolve during a series of chemical treatments.  Our lab is working to optimize the determination of cell health through multiple quantitative imaging modalities within a microfluidic system.  We have developed a high-throughput microfluidic platform that permits automated delivery of nanoliter volumes to 128 cell culture chambers contained in a 2-cm2 area.  We have validated basic fluid handling operations of the 20-inlet/24-valve microfluidic device, including the ability to tune multiple chemical concentration gradients and control fluid flow rates over a wide range.  We are using orthogonal experimental design (DEX) methodologies to devise an experiment to optimize the detection of cell health by applying multiple toxic compounds (at several concentrations each) across a human hepatoma cell line (HepG2), a common model for toxicity studies, that is labeled with a panel of markers for cell viability.  Several complimentary imaging modalities (e.g. phase contrast and multi-color fluorescence microscopies) will be used to measure cell behavior in real time or at various time points throughout the experiment.