Nicholas Palmer was investigating a biological mystery: How does actin, a common protein that plays a role in the spread of cancer in the body, lengthen and shorten during cellular movement?
Individual proteins are too small to see with most microscopes, and other techniques had provided inconsistent clues to the precise mechanism.
So Palmer, a graduate student at the Perelman School of Medicine at the University of Pennsylvania, turned to a relatively new and extremely powerful electron microscope that provides some of the sharpest-ever images of life's tiniest components.
He loaded millions of copies of frozen proteins into the sample chamber of the microscope, a machine the size of an industrial refrigerator, then waited as the images developed on the computer screen.
"When I saw this structure in particular, I jumped up and cheered," Palmer said. "As soon as I saw this, I was like, 'I know exactly what the mechanism is.'"
This ability to see individual components of the cell-proteins, nucleic acids such as RNA and DNA, lipids, and organelles as they go about their everyday work-is rapidly transforming the study of the biology behind health and disease.
Researchers at Penn Medicine are at the forefront of bringing this revolutionary imaging technique, known as cryogenic electron microscopy, or cryoEM, to improving patient health and quality of life by investigating causes and treatments for diseases such as Alzheimer's disease, cancer, and influenza.
