New Lab Device Improves Experiment Speed

A group including several Harvard researchers has developed a new microfluidic screening device that can run biochemical experiments on a much smaller, faster, and more cost-effective scale.

The team, which included scientists from the School of Engineering and Applied Sciences and other universities, said that the technology could transform the way experiments are conducted.

The device, which effectively reduces the scale of the laboratory from test tubes to water droplets, can be used in a variety of fields, with applications ranging from drug screening to biofuel development.

The scientists recently demonstrated the device’s utility in experiments on directed evolution, with results published Tuesday in the journal Proceedings of the National Academy of Sciences.

“The idea is to build a system where we can do large number of reactions very quickly,” said Adam R. Abate ’02, a SEAS post-doctoral physics student and an author of the study. “Each reaction happens in a droplet as opposed to a test tube, and therefore we can get data much more quickly than with a robot or a graduate student.”

Directed evolution—the method of artificially inducing natural selection to evolve desirable proteins or RNA not found in nature—is highly difficult to study in a laboratory setting, according to physics professor David A. Weitz, an author of the study.

The scientists first created many versions of the common enzyme horseradish peroxidase, each with a different mutation.

The standard procedure would then be to introduce each gene into yeast cells, grow the cells, collect and detect the amount of enzymes produced in each strain of yeast, and look for the most favorable strain. These are steps that, when performed with the traditional state-of-the-art robots, would have taken years and millions of dollars to complete.

But with the screening device, the entire procedure was performed in only a few hours and cost a few dollars, according to Weitz.

“Basically, we were able to test a hundred million [mutated strains] over a course of few hours, which is a tremendous speed-up,” said Weitz. “This [new technology] allowed us to ask very fundamental questions about the nature of evolution itself, how to best improve the technology to make new enzymes.”

The researchers said they were excited to debut the technology for commercial purposes. For example, Abate and other collaborators are looking to apply similar technology to find a way to inexpensively sequence an individual’s genome.

“We kept on coming up with new and unexpected areas where we can apply these things,” Weitz said.

—Staff writer Helen X. Yang can be reached at hxyang@fas.harvard.edu.