Science & Technology

A clever trick allows 20x faster imaging with an electron microscope

Two images of HeLa cells. Both were recorded in 33.6 seconds. The image on the right was taken with a voltage applied to the sample holder. Credit: TU Delft

Researchers at Delft University of Technology (TU Delft) have extended a clever trick to increase the speed of electron microscopy imaging by a factor of 20. All you need is a simple adjustment. That is, a voltage is applied to the sample holder. With this simple intervention, specimens that normally take a week to be imaged with an electron microscope can now be examined in one night or one business day.

When it comes to imaging on a very small scale, electron microscopy is unmatched.Unlike optics microscope Catch light particles, Scanning electron microscope (SEM) is Electron beam In specimens-for example, thin slices of tissue. The electrons in the beam are scattered in the tissue, and the scattered electrons are captured by the sensor. The computer then creates an image based on the number of electrons scattered at each position the beam scans.

Hard work

Electron microscopes can magnify objects up to 1 million times and examine the structure of tissues and other substances at the near-molecular level. However, mapping small objects can be a real pain, as the device works in great detail. “For example, as part of our diabetes research, we’re working with UMC Froningen researchers to create images of the islets of insulin-producing Langerhans in the pancreas,” said Jacob Hogenboom, a researcher at Delft University of Technology. Stated. “It takes about a week’s worth of measurements to make a complete image of just one slice of pancreatic tissue from a rat.”

Clever Delft tricks enable 20x faster imaging with an electron microscope

Credit: TU Delft

Hoogenboom’s research group, working on improving light and electron microscopy, has devised a clever trick to speed up this process by a factor of 20. “By applying a voltage to the sample holder, we can slow down the incoming electrons and at the same time accelerate the outgoing electrons,” he explains. “This acceleration means that the electrons hit the detector with more energy, producing more signals, which overwhelms electron and shot noise, allowing the device to measure more efficiently. . “


Researchers came up with this idea through another basic research project.In this study, they are trying to figure out what Chemical reaction Electrons enter with the material being scanned with various energies. “We don’t want to change what we scan during the scan, so our goal is to limit these reactions as much as possible,” says Hoogenboom. “We also experimented with applying electric potentials to the sample to adjust the energy of the electrons. When we realized that we could save time creating images using these electric potentials, we talked about this ourselves. We were talking. “

The great thing about this TU Delft trick is that it doesn’t require complicated adjustments. It can be used by anyone who has a scanning electron microscope. Hoogenboom: “Most of the time electronic microscope It is already possible to apply a voltage to the sample holder. People usually use this option to separate high-energy scattered electrons from low-energy scattered electrons, leaving only useful signals. But so far no one has understood how fast you can image your specimen. ”

View Electronic: Scientists Pave the Way for a More Affordable and Accessible Cryo EM

For more information:
Optimization of negative stage bias potential for faster imaging with Ryan Lane and other large electron microscopes, Journal of Structural Biology: X (2021). DOI: 10.1016 / j.yjsbx.2021.100046

Quote: An electron microscope obtained on March 30, 2021 from https: // by a clever trick (March 30, 2021) 20x faster imaging will be possible in days)

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A clever trick allows 20x faster imaging with an electron microscope A clever trick allows 20x faster imaging with an electron microscope

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