Effects of Storage Temperature and Media/Buffer for SARS-CoV-2 Nucleic Acid Detection

Abstract

Objectives: The increase in the number of patients with coronavirus disease 2019 (COVID-19) has delayed real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR), requiring proper shipping and storage conditions, especially in hot weather. This study aims to assess how some conditions, such as storage period, temperature, media or buffer, and sample types, affect the results of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-qPCR. Methods: SARS-CoV-2-positive specimens were collected from Boramae Medical Center for 2 months (from May to June 2020) and stored in different media or buffers at different temperatures. Results: As a result of examining confirmed patient samples, RT-qPCR results were not significantly affected by 2°C to 8°C storage until after 7 days. When stored at 20°C to 22°C or above 35°C, the results were affected negatively even after 1 day. Higher storage temperatures resulted in a lower probability of detecting viral nucleic acids because of degradation. Samples stored in pH-controlled media or buffer were more stable than those stored in nonbuffer states. Conclusions: These results emphasize the importance of storage temperature and media or buffer and performing RT-qPCR for SARS-CoV-2 nucleic acid detection as soon as possible after sample collection.