Quickly detect the genetic characteristics of the British variant
The Eurofins Biomnis laboratory in Ivry-sur-Seine in Val-de-Marne has developed a new screening kit and has been testing positive samples for Covid-19 since January 23, in order to provide health authorities with a map of the circulation of new variants of the coronavirus in France. This is a rapid technique: screening PCR which can analyze up to 50,000 positive PCR tests per day. To put it simply, positive tests are sent there so that scientists can identify whether or not they carry the genetic characteristics of the British, South African and Brazilian variants.
” Screening is neither more nor less than the same amplification reaction that is used for screening. The difference will lie in the fact that we are not looking for sequences that are common to the coronavirus, we will specifically look for areas of the genome which are areas that carry mutations and it is these mutations that we will amplify in a very specific », Explains François Cornu, president of the Eurofins Biomnis laboratory.
PCR screening test and sequencing: two complementary methods
Thanks to this rapid technique, the detection of the variants of the coronavirus is done in a few hours, unlike the sequencing technique which requires more time and which was until then the only method used. However, these two methods are complementary. Indeed, if this new technique makes it possible to analyze the progression of mutations, it is intended, on the other hand, to be less efficient than sequencing for detecting possible new variants.
As Dr Christophe Rodriguez, virologist explains: “ The problem is that the variants do not stop evolving and that this will require that the PCRs adapt permanently and it is not very easy to adapt the PCRs. Sequencing absolutely does not require prior knowledge of mutations, and therefore if new ones emerge, well we can find them. “.
