The Accredited Laboratories in Medicine (ALM) have plenty of work to do nationwide at the moment, because for a short time now there has been a targeted search for coronavirus mutations. Five to ten percent of all new infections are screened in this way for the British variant B.1.1.7. and for the South African variant B.1.3 variant of the virus with the aid of specially targeted PCR examination methods or else whole genome sequencing. Here, the mutant viruses often occur in clusters, which means that people from infection foci infect each other with the virus, which somewhat distorts the statistics.
So-called whole-genome sequencing, elaborate targeted testing for corona mutants from the United Kingdom and South Africa, but also from Brazil, takes a long time, about a week in total, as Hendrik Borucki of the private laboratory Bioscientia, based in Ingelheim, explains. Medical-technical assistants create 96 samples per day, which they prepare for automatic analysis in 1.6 million sequencing machines. 1,500 coronavirus samples can be processed in this way in a week, because the machine has to analyze 30,000 building blocks of a single viral genome. However, the building blocks are too long, so they have to be broken down into fragments of 250. In the process, they still have to be labeled and biochemically bound to a plate. Another 26 hours then pass for fully automated sequencing until the result is available, after which the exact sequence of the base pairs of the viral RNA (deoxyribonucleic acid) provides information about a possible viral mutation. Bioinformaticians then only have to compare them with reference sequences of the viruses already stored in the database. If the genome sequencing of the base pairs then turns out differently, it is possible to say 100 percent that a virus variant of the three countries described above is present.
The ultimately nationwide overview of virus mutations provides virologists with clarity about the distribution and about possible new infections, which can spread much faster. The Robert Koch Institute (RKI) will publish a report on this shortly.
Source: Pharmazeutische-Zeitung