You're now looking at the novel coronavirus SARS-CoV-2, the pathogen responsible for the ongoing COVID-19 pandemic and the source of half of the world's woes over the past few months.
A fresh batch of images showing the novel coronavirus (SARS-CoV-2 ) has recently been uploaded by the US National Institute of Allergy and Infectious Diseases (NIAID). The false-colored images were captured using a scanning electron microscope and color-enhanced at the NIAID Integrated Research Facility in Fort Detrick, Maryland.
According to NIAID, the images show hundreds of SARS-CoV-2 virus particles (the tiny dot-like structures) on the surface of a human cell, taken from a US patient, as it enters a state of apoptosis, aka cell death.
As you can see from the images, the coronavirus is dwarfed by the cell. Viruses are minuscule, with a generic coronavirus measuring between 120-160 nanometers in diameter. This means they are too small to be seen with a light microscope and only observable with an electron microscope. Instead of using light like our eyes, electron microscopes use electrons for imaging, scanning a specimen with a beam of electrons and recording what’s reflected back.
The coronavirus consists of little more than a single strand of RNA (a bit like half of the ladder-shaped DNA) covered in a lipid bilayer and protein spikes. Coronaviruses – a large family of genetically similar viruses, including the pathogen responsible for the SARS outbreak in the early 2000s – take their name from their protein spikes, which are said to look like a crown, translated as “corona” in Latin.
Despite their small stature, they can cause some real damage. To infect a cell, coronaviruses use their “spike” protein to bind to the cell membrane, a bit like a lock and key. Once inside, the virus hijacks the host cells' own machinery to replicate, creating thousands of copies of itself. Eventually, the host cell is overwhelmed and it effectively kills itself, causing the virus to flood out and spread to new cells. This is the part of the process you’re seeing in these new images.
If you want to see more images of the novel coronavirus, check out the NIAID's previous collection of images released last month.