Tue 20 Jul 2010
By Diana Kenney and Sarah Stanley
Friday was the last day MBL Physiology and Neurobiology students had Eric Betzig’s latest invention to explore. Two weeks ago, Betzig (left) brought his new contribution to high-resolution microscopy to the MBL from his lab at HHMI’s Janelia Farm campus and installed it in the central microscopy facility on the ground floor of Loeb.
“It’s really at the very bleeding edge,” Betzig says of his microscope, “but it’s a really good time to bring it (to the MBL), where all sorts of world-class cell biologists throw everything they can think of at it. We can learn through trial by fire what works and what doesn’t.”
The microscope combines two concepts—plane illumination microscopy and Bessel beams—to allow for high-resolution imaging within live cells. Cell components are labeled with fluorescent markers, and excitation of these markers by specific wavelengths of light allows them to be visualized by the microscope. (See video below to hear Betzig explain how his Bessel beam plane illumination microscope works).
The microscope is the just latest invention that Betzig has test-run at the MBL. In 2007, Betzig loaded his cutting-edge PALM (photoactivated localization microscopy) equipment into the back of an SUV and drove it up to the Physiology course, upon the invitation of Physiology faculty member and NIH senior investigator Jennifer Lippincott-Schwartz. PALM allows scientists to discriminate molecules only two to 25 nanometers apart, a vast improvement on the previous 200-nanometer limitation. At the MBL, Betzig, Lippincott-Schwartz, Jim and Cathy Galbraith of the NIH, Hari Shroff, a former Physiology student, and students then in the course worked feverishly around the clock with PALM. “By the end of two weeks, we had gotten PALM to work with live cells for the first time!” says Lippincott-Swartz. Not only that, but they got PALM to work with two colors of fluorescent probes rather than one, and demonstrated that it could be used to track single molecules in live cells. “It was a spectacular session, and it led to several publications,” Lippincott-Swartz says.
What’s next for Betzig? “I don’t know how many times we’ll invent a new microscope,” Betzig says, “but when we do, the MBL is a good place to be for that kind of intense trial to try to find out what works.”
Betzig discusses the new Bessel beam plane illumination microscope:
In this clip, Betzel’s microscope allows for visualization of histones – proteins associated with DNA – inside a pig kidney cell:
Here, the microscope reveals a network of mitochondria – cellular components that synthesize ATP, the “fuel” of the cell – inside a human cancer cell: