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| Pin-Fang Chen '09
examines an eukaryote at a magnification of 12,000 times using Wesleyan's
new Transmission Electron Microscope. Wesleyan acquired two new high-tech
microscopes. |
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| Posted 08.07.07 |
New Microscopes Aid Wesleyan Researchers
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Wesleyan’s Advanced Instrumentation Center has
scoped out better way to conduct infinitesimal scientific research.
In the past six months, the center has acquired a new, state-of-the art
scanning electron microscope (SEM) for 3-D imaging, and a transmission
electron microscope for 2-D sample images. These microscopes are used by
faculty, graduate and undergraduate students.
“These microscopes are allowing Wesleyan scientists to conduct research at
levels never done before,” says Joe Bruno, vice president for Academic
Affairs and provost. “As more and more
 scientists
pursue the study of novel materials and their applications, the ability to
see surface morphology at high magnification is of considerable importance.”
Bruno, also a professor of chemistry, has already used the new scanning
electron microscope to study the surfaces of interesting hybrid
organic-inorganic solids made by a method known as the sol-gel process.
The new SEM is a JEOL JSM-6390LV model. The instrument is operated by
placing a three-dimensional sample into a vacuum-tight chamber. The SEM
creates highly-detailed three-dimensional images by bouncing and collecting
electrons instead of light waves. The magnified image appears on a nearby
computer screen.
“We are very fortunate to have this new SEM. It has replaced an old Amray
microscope that was a from the 1970’s,” says Jeff Gilarde, director of
Scientific Imaging. “This machine is well-automated, it has a higher
resolution and its images are beautiful.”
 The unit was supported by the Kresege Foundation Challenge for Science
Equipment Endowment.
Tim
Ku, assistant professor of earth and environmental sciences, has used the
SEM to observe phytoplankton samples from a local lake (see image at right,
top). Jim Greenwood, research assistant professor of earth and environmental
science, has used it to examine mineral and element content in meteorites
(see image at right, bottom).
“This thing’s amazing. It conducts an elemental analysis on the martian
meteorite and tells us what’s it made of,” Gilarde says, browsing digital
images of the sample. “It shows that it has some traces of calcium and
sodium."
The lab’s other new microscope, the Transmission Electron Microscope — or
TEM — views samples in two-dimensions, but has the ability to magnify the
finest cell structures. The instrument is a JEOL JEM-1011 model.
Prior to viewing, a sample will be sliced by an ultra microtome, which can
cut biological specimens into extremely thin slices. Gilarde says the
machine could slice through the edge of a single piece of paper six times.
The super-thin samples are placed onto a slide inside the TSM.
On July 25, Hughes Fellow Pin-Fang Chen ’09 used the TSM to examine the
eukaryote tetrahymena. The microscope is used in the dark and
researchers use a computer to operate the instrument.
Chen magnified the eukaryote 12,000 times, although the TEM is capable of
enlarging an object 300,000 times.
The TEM was a gift from Board of Trustee member Frank Sica '73.
Both microscopes are located in the Advanced Instrumentation Center’s
Scientific Imaging Laboratory, located under the pathway between
Hall-Atwater Laboratory and Shanklin. For more information on the new
microscopes, contact Jeff Gilarde at
jgilarde@wesleyan.edu.
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By
Olivia Bartlett,
The Wesleyan Connection editor |
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