Stability of SARS-CoV-2 respiratory samples in non-freezing condition: importance for tropical countries under heavy diagnostic demand.

Keywords: real-time PCR; sample stability; SARS-CoV-2 EN real-time PCR sample stability SARS-CoV-2 e78 e80 3 04/25/23 20230515 NES 230515 To the Editor, We read with great interest the article "SARS-CoV-2 RNA identification in nasopharyngeal swabs: issues in pre-analytics" by Basso et al. (2020), particularly regarding the findings on sample stability [[1]]. With those results in mind, we aimed to evaluate whether nasopharyngeal swab samples maintained viability for SARS-CoV-2 RNA detection through qRT-PCR following different storage periods in various conditions in southeastern Brazil. The coefficient of variation (CV) of observed Ct from samples maintained at environment temperature ranged from 1.3 to 5.3% for I E i gene; 0.4-6.8% for I RdRp/S i and 0.81-4.8% for I N i gene (data not shown). [Extracted from the article]