Evaluation of long-term stability of SARS-CoV-2 nucleic acid extracted from human nasopharyngeal samples

The maintenance of SARS-Cov-2 RNA samples poses a new challenge for laboratories and researchers. In addition, it is a requirement in order to identify what strain of the new coronavirus is predominant in a region, for instance. Therefore, it is a must to keep the quality and viability of stored RNA to respond to this and other valid questions. In other to test the quality of our samples and storing protocols, we randomly checked RNA samples four different times over one year using a second RT-PCR assay after the first test. The virus genes, N1 and N2, showed no significant increase in the media of the CT value between the first assay and subsequent times with p > 0.05. However, the human RP gene showed differences in the first three times analyzed, but within the acceptable sample cut-off, according to the test manufacturer. After one year, the RNA extracted from human nasopharyngeal specimens are viable to detect the virus SARS-CoV-2 genes with minor changes.