The display describes the use of microscopes -- ranging from the light microscope to the sophisticated Scanning Electron Microscope (SEM) -- in studying the tissue changes that initiate the blockages in the arteries of the heart that characterize atherosclerosis.
Presenting the information as a detective story, the display begins with a section titled "The Crime." The text states: "A mob of trespassers has clogged a major artery, blocking the flow of important traffic. This dangerous condition, called atherosclerosis, may lead to heart attack or stroke."
"The Detective" -- the title of the next display section -- is illustrated with a poster-size photo showing Rob Apkarian, technical director of the Yerkes Integrated SEM Facility, while working at a light microscope. The caption explains that Apkarian is using a "computer-controlled light microscope to examine the scene of the crime: the inside wall of a human blood vessel. The microscope's lenses enlarge the image by `bending' light rays coming from the tissue's surface. The magnified image is digitized for computer storage and display."
The detective story concludes with a section titled "Closing in on a Crime Ring," illustrated by a Yerkes SEM image of the blood vessel at 2,000 times magnification. A ring of white blood cells is visible on the vessel wall.
The display compares the light microscope and the SEM: "The evidence that we can collect with a light microscope is limited. It can magnify only up to 2,000 times, and even the final image may be dark and murky."
The text also states: "It can never distinguish objects close in size to the tiny wavelengths of visible light. Light microscopes provide only two-dimensional images of a specimen's surface.
"But a newer technology can help us find the clues we need. The high-tech microscope pictured here can magnify a specimen up to 1 million times, producing highly detailed 3D images."
In a section titled "This Tale is Brought to You By," Apkarian's role in creating the exhibit is acknowledged. Also assisting SciTrek were Yerkes photographer Frank Kiernan and Cathy Yarbrough, Yerkes chief of public affairs.
Reprinted with permission from the Yerkes Employee Bulletin.