The SEM is a technique based on the principle of electron-matter interactions which makes it possible to obtain high resolution images of a surface.
An electron beam strikes the surface of a sample, generating the emission of a spectrum of particles in the form of radiation. The treatment of these different radiations provides information on the material of the sample.
The images help illustrate the intensity of the respiratory tract infection with SARS-CoV-2, the virus responsible for COVID-19.
In the laboratory, the researchers inoculated the coronavirus into human bronchial epithelial cells. The team captured images of the cells 96 hours later using SEM.
Colorized images show virions (red) with strands of mucus (yellow-green) attached to the ends of the eyelashes (blue).
Virions are the complete infectious form of the virus released to respiratory surfaces by infected host cells.
As for the cilia, they are hair-like structures on the surface of airway epithelial cells that carry mucus (and trapped viruses) out of the lungs.
One of the magnified images shows the structure and density of virions (in red) of SARS-CoV-2 produced by the epithelium of the human airways.
These images help illustrate the incredibly high number of virions produced and released by cells inside the human respiratory system.
The high viral load is one of the sources of the spread of the infection. It is probably the cause of the high frequency of transmission of COVID-19 between people. These images illustrate this viral load and strongly advocate the use of masks by infected and uninfected people in order to limit the transmission of SARS-CoV-2.
Details of the work of researcher Camille Ehre and her colleagues are published in the New England Journal of Medicine (New window) (in English).
Source: Radio-Canada | Science