Rad project spotted over at phys.org – the microfluidics system researchers required didn’t exist, so they made it themselves!

In a paper appearing online this week and on the cover of July’s issue of Nature Biotechnology, Bashor and colleagues from Boston University (BU) and the Massachusetts Institute of Technology unveil eVOLVER, a system that combines the control of automated cell-culturing systems that can run continuously for months with the scale of high-throughput systems that grow dozens of cultures at once.

Bashor, assistant professor of bioengineering at Rice, first thought of the idea for eVOLVER three years ago while working as a postdoctoral researcher at BU.

“One thing we were working on was antibiotic resistance,” he recalled. “A lot of times, antibiotic resistance shows up when you administer the drug continuously. So I was thinking, what if you administer it in pulses? How long are the pulses? Where do you see antibiotic resistance evolve? Where do you see it not evolve? Is there a way to systematically see what the temporal features of antibiotic administration gives you?

“If you plan a time course and say, ‘I want to do this one every 15 minutes, I want to do this one every hour,’ and so on, you quickly realize that it’s impossible without automation,” he said. “Not to mention that antibiotic resistance often shows up in time scales of weeks rather than days. You need something automated that can run for several weeks, with dozens or hundreds of samples that are individually controlled and monitored.”

Abstract from Nature Biotechnology, published in June:

Precise control over microbial cell growth conditions could enable detection of minute phenotypic changes, which would improve our understanding of how genotypes are shaped by adaptive selection. Although automated cell-culture systems such as bioreactors offer strict control over liquid culture conditions, they often do not scale to high-throughput or require cumbersome redesign to alter growth conditions. We report the design and validation of eVOLVER, a scalable do-it-yourself (DIY) framework, which can be configured to carry out high-throughput growth experiments in molecular evolution, systems biology, and microbiology. High-throughput evolution of yeast populations grown at different densities reveals that eVOLVER can be applied to characterize adaptive niches. Growth selection on a genome-wide yeast knockout library, using temperatures varied over different timescales, finds strains sensitive to temperature changes or frequency of temperature change. Inspired by large-scale integration of electronics and microfluidics, we also demonstrate millifluidic multiplexing modules that enable multiplexed media routing, cleaning, vial-to-vial transfers and automated yeast mating.

Read more here.