AMES, Iowa Sanjeevi Sivasankar was looking for a better tool to study how cells adhere to each other.
Cells have surface proteins, called cadherins, that help them stick together. Different kinds of cells have different kinds of cadherins. The typical tools for observing and measuring those proteins focus on tens of thousands of them at a time providing data on the average molecule in a sample, but not on a single molecule. Sivasankar, an Iowa State University assistant professor of physics and astronomy and an associate of the U.S. Department of Energy's Ames Laboratory, wanted to study them one at a time.
And so as a post-doctoral researcher at Stanford University and the University of California, Berkeley, who worked with Steven Chu, the current U.S. Secretary of Energy and co-winner of the 1997 Nobel Prize in Physics Sivasankar came up with the idea of developing and building a unique, single-molecule microscope.
"These fields are so technologically driven, you have to invent new stuff to discover new things," Sivasankar said.
The new idea was to combine two single-molecule technologies that had been used separately: atomic force microscope technology that manipulates molecules and measures forces; and fluorescence resonance energy transfer technology that observes single molecules at very high resolution.
Using one or the other technology is like "having hands but no eyes or eyes but no hands," said Sivasankar. "We can combine these two technologies into one instrument."
This type of instrument could advance studies in biomedical research, drug discovery, cancer diagnostics and bio-sensing applications.
Sivasankar brought the idea for an integrated, single-molecule instrument to Ames when he started at Iowa State and the Ames Laboratory in 2008. He's since built a laboratory prototype and improved its measurement capabilities and efficiency.
Sivasankar and his research group Iow
|Contact: Sanjeevi Sivasankar|
Iowa State University