This is it.
This is SARS-CoV-2.
The novel coronavirus that first appeared in humans in late 2019.
These are some of the first close-up views of the virus, made using a very specific imaging
technique.
That can see things far too small to be visible under a normal microscope.
They show us how the virus moves inside the human body,
And how it hijacks our cells, using these.
These spikey crowns give the coronavirus its name.
And they’re the key to understanding how to beat it.
To get this right, I need to bring in two experts.
The first is my colleague Liz’s dad, Frank.
He teaches materials science and engineering at Ohio State University.
Yes! So that’s how you pronounce it. Okay that’s a good start.
And the other is Beth Fischer.
Her team at NIAID, the National Institute of Allergies and Infectious Diseases, created
those initial images of the virus.
The ones you’ll start to notice embedded in news articles around the internet.
So let’s start with how these images were made.
The first thing you need to know is that the coronavirus it’s very, very, very, small.
Around 100 nanometers.
To put that into context, if you take out a ruler and look at one of the millimeter
markings, you could fit 10,000 virus particles inside of that.
At that size, it’s invisible to us, even under a standard light microscope, like the
one you might have used in grade school.
That’s because the smallest wavelengths of light humans can see measure about 400
nm.
Not small enough for the coronavirus to be visible.
In order to see something that small, you need an electron microscope.
How does it actually differ from what we would think of as a microscope?
Instead of light we’re using electrons.
And electrons you think of as particles.
But if you take the electron, strip it off of the atom, and accelerate it in a field
and make it fly really fast.
And that wavelength is much, much smaller than the light waves we use in a standard
microscope.
So now you’re like 6, 7, 8 magnitudes smaller in size.
So now you can see smaller stuff.
If you look through NIAID’s coronavirus Flickr page, you’ll come across two distinct
types of images.
SEM and TEM.
They’re made using two different types of electron microscopes.
A Scanning Electron Microscope, or SEM, scans the surface of a sample and records what bounces
back, sort of like how satellite imaging works.
It gives you the basic topography of whatever you’re looking at, with realistic lighting
similar to photography.
Shadow and relative size of objects shows you their placement and how they move through
the cell. A Transmission Electron Microscope, or TEM,
goes way deeper.
It records the inner details of a sample by transmitting electrons through it.
And projecting a cross section of its inner structure.
So it’s part of the basic science research to try and understand structurally what’s
going on
Images from both microscopes are taken in black and white, the color is added later
for clarity.
Like in this SEM image, where virus particles, colored in yellow, are seen emerging from
the surface of a cell, colored blue and pink.
When examined together, these images can help scientists start to figure out how coronavirus
works.
There’s ways to start then understanding how is it getting in a cell?
How is it harnessing that cell machinery to make more of itself?
Can you just tell me kind of what we’re looking at here?
So this is a single viral particle.
And the yellow you see is the core of the virus itself.
And then the corona, where coronaviruses get their name, is that halo around it that’s
in orange.
That corona is the key to understanding how the virus hijacks our cells.
The spike proteins that surround the virus attach to a host cell’s membrane and then
penetrate it.
Once it forces its way in, it spreads its RNA around the host cell, multiplies, exits,
and repeats, which makes us sick.
So if we can bind those spike proteins up with something like an antibody, it’ll prevent
them from being able to attach and enter cells.
Which is exactly how we’ve beaten back viruses with similar spiky proteins before.
This is a 3D rendering of the ebola virus.
You see all those proteins on the surface – when we talk about the spike proteins,
that’s what we’re talking about, no matter which virus we’re looking at.
This is HIV actually.
So this is printed after we do our cryo-TEM.
And you can see all these tiny little proteins and how they’re distributed on the surface.
And these are the proteins that we tend to target for vaccine development.
Is there anything, about the images specifically, that you’d want to share with our audience
that maybe you think would be helpful for them to know?
I think when you can face your enemy, it takes a little bit of the fear factor out of it.
I think it’s just understanding what it is we’re looking at and how it works within
our bodies.
But to show that
I think is important to know.