A rapid test has been developed which in just two hours allows to identify the three variants of the SarsCoV2 virus in circulation in Italy and which at the end of February could be available to all laboratories that carry out the analysis of molecular swabs.
"It is the tool that allows you to make a first screening on the swabs that have been positive for the molecular. Then it will still be necessary to sequence the genetic material of the virus both to have the definitive confirmation, and to identify any new variants other than English, the Brazilian and the South African, "virologist Francesco Broccolo, from the University of Milan Bicocca and director of the Cerba laboratory in Milan, told ANSA.
Contrary to the test developed at first and based on a patented technology, the new test was developed by Broccolo himself with an Italian company and is based on a modification of the polymerase chain reaction (PCR) technique , used to amplify the genetic material of the virus taken with swabs.
Called PCR Multiplex, the technique specializes in identifying mutations within a gene using molecular probes labeled with fluorescent molecules (fluorochromes).
"The latter identify the variants," said the virologist.
"Each variant has a modality that distinguishes it and it is therefore possible to identify them by looking directly for these characteristics, even before sequencing".
For example, the probe specialized in searching for the English variant detects the mutation 69-70 and 501, while the Brazilian and South African variants are detected by the probe that detects the 484 mutation of the S gene of the Spike protein.
"This technique - said Broccolo - can be easily available in all laboratories, both with the kit already validated and with reagents and probes designed 'home made', as long as they are subjected to internal validations with the regional reference laboratories: for this reason - he concluded - it is a tool that could help accelerate the search for variants in our country ".
