Biology on a Chip: Big Changes Writ Small
Ken Shepard | Electrical Engineering
Welcome to the post-modern biology lab. It's made of silicon, measures 5mm on a side, and costs just $20. It can also be deployed to harsh or distant locations and when an experiment is complete, it can be discarded. Welcome to Ken Shepard's lab—or at least one of the many he is designing.
Shepard and his team at the Bioelectronics Systems Lab employ the same technology used in the integrated circuits industry to build their own micrometer-scale arrays of sensors that can detect biological molecules or select strands of DNA. "There are definitely other techniques for doing these things, but they're difficult, time-consuming, and expensive," said Shepard, Professor of Electrical Engineering at SEAS. "The goal here is to come up with something that's as sensitive as the most sensitive instruments, if not more, and reduce everything else about it."
Very often, in order to detect a particular molecule, they have to first be labeled—physically attached to something such as a fluorescent dye that permits detection. Shepard and graduate student Matthew Johnston aim to circumvent this laborious process by directly detecting the weight of individual molecules.
When target protein molecules bond to the surface of one of their chips, it causes the frequency of a vibrating piezoelectric crystal to change. The magnitude of the change quickly confirms the presence of their target.
In their first test of the lab-on-a-chip, Shepard and Johnston are using a sensor designed to search dust samples for common airborne allergens that have been linked to high childhood asthma rates in urban areas. Shepard also envisions a day when his chip-based labs could be used to quickly and easily detect blood-borne cancer proteins.
