With the entire world shut down in response to a seemingly invisible enemy, the few photos that we have of the novel coronavirus — also known as SARS-CoV-2 — seem both otherworldly and banal. How can something so small, so alien-seeming, wreak such havoc? That images exist of the virus at all is remarkable — especially because they are microscopic photos brought to life through a process not unlike an illustration. We spoke with Michael Peres, who teaches biomedical photographic communications at Rochester Institute of Technology’s School of Photographic Arts and Sciences, who explained this technical process in the JPG newsletter. Part of that interview is republished here, along with a wide array of examples of germ photos.
WHAT ARE THE STEPS IT TAKES TO MAKE A PICTURE OF A VIRUS?
It's a process that starts out with the virus that is collected in some way shape or form, and taken to a place that’s safe. Ebola, SARS, HIV, and many other viruses that have infected humans are of course dangerous and the management of those viruses, dead or alive, is important.
So these viruses, if they’re looked at in a scanning electron microscope (SEM), they have the moisture removed, and then put in a vacuum chamber of some sort, which is part of the microscope, and then they are bombarded with electrons. The electrons reflect off the surface of the material, and then they are captured by a detector, and the detector forms an image that you can see and record, which is a monochromatic imaging process.
You have to be efficient, because these biological materials can’t be in a microscope and bombarded with electrons for infinite amounts of time without them changing or being destroyed.
With a scanning electron microscope you see the outsides of things, with a transmission electron microscope you can see the inside of things. To make a TEM work, scientists cut the virus in some way — you need to be highly precise and highly technical and use very sophisticated equipment to section it. Then certain types of heavy metals stains are added to it, so that it has a kind of density for electrons. Like light, heavy metals on a biological material block electrons or transmit electrons, leading to white regions of your image or dark regions of your image, which then of course is captured with digital technology.
Then you have the image, which is black and white, so you have the artist come in to add color called false or pseudo-colorizing color. People expect to see things in color. When we see grayscale images, there is an immediate feeling that they are uncommon.
SO THIS IS A SUPERTECHNICAL PROCESS THAT RESULTS IN A DRAWING?
Yup! The microscope uses electrons, not light, and they can be super expensive; they have resolutions that are on the scale of nanostructure and are measured using Angstroms, super high-res instruments that can easily go to 100,000 times magnified. They look at things that are infinitely tiny, so tiny that you know on a light microscope if you were even able to detect one, that would be extraordinary.
If the EM images require further enlargement with clarity, there is now the need to make an illustration or a derivative piece based on what can be seen within the image. In the illustration, color and other elements of the drawing are somewhat speculative, because no one has actually seen the virus in color, the way that you’re seeing them illustrated. What we see is an interpretation of what we believe we saw in an image by a highly trained illustrator.
It's much different from illustrations in advertising. In advertising, an illustrator interprets a thing, and they try to make it look a certain way for sales or for emotional reasons. In science, you tell science facts, not science fiction, so the highly detailed illustrations are used to communicate information about what the actual virus really looks like.
WHAT IS THE TRAINING?
Professional education in imaging is not at the same scale as you might expect. You don’t go to school really to be an electron microscopist. You don’t go to school to be a light microscopist. It’s a tool used in science and different organizations have different access to different equipment. It's often just on-the-job training, OJT. At RIT, we have a photographic sciences degree program where light and scanning electron microscopy are possible class choices
So someone who is working on a master’s in biology might have access to an SEM or TEM or other cohorts in places called imaging centers. The highest number of scientists that are working probably don’t have any formal imaging training. Their craft is about science, and they use the microscope as a tool, like beakers.
WHY IS IT IMPORTANT FOR SCIENTISTS TO SEE WHAT THE VIRUS LOOKS LIKE?
I think, like any process, where people are learning new things, visualized data helps people to analyze and then deduce. It's like trying to describe a color in words, describe blue in words. You can’t do it. Pictures help a scientist describe a procedure or a process or an organism in a way that words would be woefully inadequate alone
These illustrations can help improve and better the science around these organisms by having some type of visual, so that the next study or antibody test or experiment can be based on knowledge.
I think it’s easy to look for photos and take for granted that there is a picture for everything, that we accept that this isn’t reality. It's a rendering.