Antisense oligonucleotide to SARS-Cov-2 trs gene: antiviral activity on an in vitro model and possibilities of vital and postmortem diagnosis of COVID-19.

The data on the relevance of the 5 -AGC CGA GTG ACA GCC ACA CAG antisense oligonucleotide for binding to the trs-gene of the SARS-CoV-2 virus, which causes the new coronavirus infection COVID-19, are presented. The high stability and conservatism of this section of the SARS-CoV-2 genome is shown, which allows it to be used as an application point for antisense oligonucleotides. By evaluating plaque inhibition, the ability of this antisense oligonucleotide with phosphorothioate and 2-oxymethyl modification to suppress viral replication was found. The effective dosage reducing the virus titer by 50% is 3.84 mcg/ml. No toxicity was shown up to a dosage of 100 g/mL, which is more than 28.8 chemotherapeutic index. The ability of this oligonucleotide conjugated to the fluorescent dye TAMRA to detect the SARS-CoV-2 virus in the fluorescent hybridization reaction in situ in cytological preparations of nasopharyngeal smears and blood smears, as well as in histological preparations of internal tissues is shown.