How it Works: Microscopy and Imaging

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SH1 is an Halovirus which infects marine archeal microorganisms. SH1 has a protein shell with icosahedral symmetry and an underlying lipid bilayer, which coats the viral genome. The dimensions of the icosahedral capsid are 78.5 nm edge to edge. The Figure shows a section of the electron density map, showing the individual protein subunits – nearly 1,700 of which make up a single virus particle.

Courtesy of Luigi De Colibus, Tom Walter, Juha Huiskonen, Elina Roine, Dannis Bamford, Dave Stuart, Division of Structural Biology, Nuffield Department of Medicine, University of Oxford.

 

Introducing science's secret weapon


We’ll start with the simple stuff: microscopy is pretty much what it sounds like – using microscopes to study small objects. And imaging is the process by which the data gathered during microscopy is turned into an image. It seems pretty basic, but these terms encompass a vast range of advanced techniques. Together, microscopy and imaging are a crack team that have revolutionised science and shaped the modern world. 
 
 

What is it?

Microscopy works by diffracting, reflecting or refracting light. And this is true whether you’re in your house looking through a magnifying glass or at a world-class science facility, using an electron microscope.
 
With a standard microscope, your sample sits on top of a lighted stage. Light from beneath the stage shines through the sample and hits lenses inside the microscope, which then focus the light to produce a magnification effect.
 
Modern electron microscopy works in a similar way, but rather than placing the sample on a lighted stage, you place it on a sample holder and then fire an electron beam at it. These incredible microscopes offer scientists more powerful magnification and higher resolution images. With a normal microscope, you can look at tiny things like cells and bacteria; but with an electron microscope, you can see atoms and molecules so small that you could fit millions on a pinhead.
 
 

The History

Microscopes have been in use since the early 17th Century when Galileo and his contemporaries began constructing the handy tools for use in their experiments. One of the first documented uses was to draw painstakingly detailed pictures of insects and their anatomical structure. Already, microscopy was helping scientists to see the world in a completely new way.

 
But the use of microscopes in science only really took off in the 19th century, when the modern system of illuminating samples with a lighted base was developed. By the 20th century, microscopes had given scientists a fuller understanding of cells, proteins, and bacteria; in essence, microscopes had helped us work out the stuff life was made of. 
 

The Technique

These days, scientists still rely on microscopes to carry out their research, but they also have access to equipment that’s far more advanced.
 
Electron microscopes work by firing fast moving electrons at a sample. The wavelength for electrons can be about 100,000 times shorter than the wavelength of visible light – this means that it can pick up smaller things that would otherwise get lost in the gaps between visible light waves.
 
Because electron microscopes are so powerful, we’re now able to see things that the scientists of the 17th century could never have imagined. Where they saw the individual veins in an insect’s wings, we can see the molecular mechanisms that create those complex patterns. From the proteins that help viruses to function, to the individual particles of pollen on a bee’s legs, electron microscopes are helping to reveal a side of the world never seen before.
 
 
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Artist's impression of Diamond's new I14/Cryo EM facility

Microscopy and Imaging at Diamond

Diamond is one of the world’s most powerful scientific machines and it supports a range of scientific techniques. Whilst Diamond itself creates synchrotron light, a new electron microscopy facility is currently under construction on the site. This new facility will house four electron microscopes.
 
The electron microscopes won’t be using Diamond’s powerful synchrotron light, but the new techniques and approaches that electron microscopy supports will perfectly complement the existing beamline facilities at Diamond.
 

Microscopy and imaging has come a long way over the past 400 years, but technology is increasing at an astonishing rate. Machines like the new electron microscopes at Diamond are pushing the boundaries of what microscopy and imaging can achieve, helping scientists to look deeper and deeper into the intricate structure of our world.  

 

 

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