French scientists have determined the optimal mode of temperature treatment of biomaterial samples of patients with coronavirus infection for laboratory research. In these conditions, a dangerous virus becomes as safe as possible for medical staff. Preliminary results of the experiment are published in the electronic scientific library bioRxiv.
The researchers conducted a series of tests by heating samples of the coronavirus strain at different temperatures in two living conditions â€“ a sterile environment and a simulated real biomaterial ("dirty" environment). It was found that with the recommended assay processing procedures, which involve heating to 56 Â°C for 30 minutes or 60 Â°C for 60 minutes, the coronavirus retains the ability to reproduce. This increases the risk of infecting people.
"Only the Protocol [heating mode] 92 Â°C for 15 minutes was able to completely inactivate the virus, while the other two protocols led to a clear reduction in infectivity, but with residual infectivity. There was no difference between clean or" dirty "conditions [for the coronavirus]," the study authors stressed.
Scientists believe that the existing methods of processing patient tests are also effective, since patients with a coronavirus infection, even in the acute stage, have a low viremia of the coronavirus â€“ the activity of its penetration into the blood.
"Considering that patients with a coronavirus infection have low viremia even in the acute stage of the disease, [these] protocols, usually used before blood collection for analysis, seem sufficient to inactivate SARS-CoV-2. Samples that are processed appropriately will also be suitable for detecting viral RNA. However, when processing samples of the respiratory tract, which bear much higher viral loads, only the Protocol of 92 Â°C-15 minutes showed complete inactivation," the scientists concluded.