Published on March 2nd, 2010 | by Tina Casey0
Harvard's Nano Sized "Lab in a Pocket" Could Speed Discovery of New Biofuels
Leave it to Harvard University to invent an entire laboratory the size of an iPod nano. The device, which actually is slightly smaller than an iPod nano, makes it possible to sort enzymes and compounds 1,000 times faster than the much larger equipment in use today, making it not only small but energy efficient, too.
The new device could precipitate a sea change in the way that new biofuels are developed. In particular, new biofuels based on microbes could be developed in a relatively short time, compared to a years-long sorting process with conventional equipment. And of course, that’s just a taste of things to come.
Harvard and the Sustainable Laboratory
The invention, called a microfluidic sorting device, is part of a trend toward finding more energy efficient, low cost, and sustainable methods of scientific investigation. Conventional sorting equipment is essentially a robotic process that requires energy and reagents. Harvard’s new device uses 10 million-fold less reagent and presumably far less energy; its inventors anticipate that it will reduce screening costs by one million-fold. The project was a team effort that also involved MIT, the Universite de Strasbourg, YNano LLc, the National Science Foundation, the Centre National de la Recherche Scientifique, the Massachusetts Life Sciences Center, and the Agence National de la Recherche. It takes a village, right?
How it Works
Basically the name “microfluidic sorting device” says it all. In this process, microscopic drops of liquid pass through a sequence of nanotubes that fork in two directions. The drops are treated with a surfactant to prevent sticking and clumping, so they act more like marbles in a chute than normal drops of liquid. Trapped within each drop is an individual cell. When a drop reaches the fork, a laser measures the level of fluorescence in the cell. The higher the fluorescence, the higher the cell’s activity level, and the more desirable it is. The active cells are pulled into the “keep” fork by an electrical force called dielectrophoresis. The other cells drop off into the “discard” fork. In one demonstration, the device sorted 100 million (yes million) variants of a high-efficiency enzyme, evolving it into an enzyme that was even more efficient — so efficient that it practically reached its theoretical maximum (that would be an enzyme that has a production capacity equal to the number of substrates that it encounters).
What This Means for Biofuels…and Energy Efficient “Green Cleaning”
The device could lead to a far more rapid means of identifying biofuel-producing organisms and improving their efficiency, possibly in a matter of months rather than years. Even with conventional lab technology, microorganisms are already elbowing crop-based biofuels aside. Just a couple of recent examples are MIT’s biofuel producing bacteria, and the glycerin-gobbling biofuel microorganisms developed by Rice University. The device also plays right into the EPA’s push for low cost, energy efficient ways to clean up contaminated sites – which in turn plays into the EPA’s newly launched programs for reclaiming brownfields for renewable energy installations. Instead of digging up contaminated soil and dumping it elsewhere (which creates a huge carbon footprint), the new approach calls for using low cost, energy efficient on site solutions. This might include using vitamin B-12 or potassium lactate to stimulate the growth of soil dwelling microbes that “eat” pollutants. For that matter, specially engineered microbes can even be used to convert wastewater to bioplastics.
Image: iPod nano by SkitterzPRO on flickr.com.