In an amazing feat of microscopy, scientists have been able to produce a video showing a tiny virus circulating around cells prior to infection.
“What we found is that the virus will have a lot of transient contacts, very short contacts, with a lot of cells before it binds to a particular cell,” Kevin Welsher, an associate professor of chemistry at Duke University, said in an interview with quirks. & Quarks presents Bob McDonald.
The improvement over previous techniques for capturing this type of activity is like the difference between a modern Hollywood movie and a stuttering flip book.
Welsher said that he and his colleagues have been developing this technique for seven years and have published their findings in the journal Nature Methods.
Their breakthrough came when they figured out how to track the virus as it moved between the three-dimensional layers of epithelial cells. These are the cells that line the surfaces of the body, such as the nose, lungs, and gut, that are the first to come into contact with viruses.
Scientists are interested in capturing the entire infection process to learn more about how a virus, such as the COVID-19 coronavirus, can cross the mucous layer and enter cells, such as those found in the lungs, where it can potentially wreak havoc, as seen. in the X-ray image on the left. (Ronny Hartman/AFP/Getty Images)
Scientists are eager to gather more details about how viruses hijack these cells, so this new 3D microscopy could improve their ability to watch the process unfold.
Welsher describes the movement of the virus as a “random walk” in which thermal energy manifests itself as small random movements in all three dimensions. That, over time, propels the tiny viral particles through the extracellular medium.
“Before what we were doing here, the common way to look at a three-dimensional system was to take images of each segment of the system and build it into one overall volume,” Welsher explained.
But the time it takes for the camera, with its fixed field of view, to move to different angles to capture the next frame of the moving target means that details about the fast-moving virus they are trying to capture are lost.
That’s valuable imaging information that isn’t recorded, which Welsher said reveals his new technique.
They do this by blocking the camera’s field of view on the viral target, like a helicopter on a high-speed car chase.
The research team’s video only captured part of the infection process where the virus binds to the cell. Welsher said the researchers’ ultimate goal is to capture the entire infection process as a virus first makes its way through the mucus layer lining epithelial cells and eventually enters a cell to replicate.
CLOCK | Real-time images of viruses before they attack a cell:
Produced and written by Sonya Buyting.
Source: news.google.com