The Eurofins Biomnis laboratory in Ivry-sur-Seine (Val-de-Marne) has been testing positive Covid-19 samples from all over France since Saturday, January 23, day and night. The goal: to provide health authorities with a map of the circulation of the different variants of the virus. The British version on one side, and the South African and Brazilian variants on the other, which the laboratory cannot yet differentiate.
A few thousand samples have already arrived. “But not at all up to the number of positive patients in France, explains Sébastien Guibault, director of the Ivry-sur-Seine site. Every day, we receive a little more than the day before, as and when the communications made by the health authorities. “
93 samples analyzed at once
The vials are first placed in an oven, in an oven, to be decontaminated. “The objective is to protect our teams when opening the bags.”, explains Sébastien Guibault. Then direction of the automatons, which will prepare the sample so that it undergoes a second PCR analysis. “We load the tubes into a pipetting machine, details the director. In order to extract a small part of the sample and position it on a microplate. Each plate contains 93 patients. Then, we prepare it to be able to perform the RNA extraction “, this famous copy of the DNA of the virus.
– Sarah Calamand
Photosensitive reagents
The extract is then heated so that it can multiply, so that there is more material to study. Now comes the addition of light sensitive reagents. The reaction is then modeled in the form of curves, which laboratory technicians will study. “We treat each patient one by one, explains Aurélien Bizet, one of the technicians working on a series of analyzes. We look at the appearance of the two curves. Depending on which is high, it is concluded whether it is the English variant or the classic coronavirus. If both are high, then we are dealing with the over-African variant. “
The data is then validated by a medical biologist and compiled to be transmitted to the authorities. The Covid platform at the Ivry-sur-Seine laboratory is capable of analyzing up to 50,000 samples per day. Research is continuing to adapt the analysis methods if new variants of the virus are discovered.
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