Prolonged Unfrozen Storage and Repeated Freeze-Thawing of SARS-CoV-2 Patient Samples Have Minor Effects on SARS-CoV-2 Detectability by RT-PCR.
J Mol Diagn
; 23(6): 691-697, 2021 06.
Article
in English
| MEDLINE | ID: covidwho-1179822
ABSTRACT
Reliable transportation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patient samples from a swabbing station to a diagnostics facility is essential for accurate results. Therefore, cooling or freezing the samples is recommended in case of longer transportation times. In this study, SARS-CoV-2 detectability by RT-PCR was assessed after prolonged unfrozen storage or repetitive freeze-thawing of SARS-CoV-2 samples. SARS-CoV-2-positive patient swabs stored in viral transport medium were exposed to different temperatures (4°C, 25°C, and 35°C) and to repetitive freeze-thawing, to assess the effect of storage conditions on RT-PCR detection. SARS-CoV-2 RNA was still reliably detected by RT-PCR after 21 days of storage in viral transport medium, even when the samples had been stored at 35°C. The maximum observed change in cycle threshold value per day was 0.046 (±0.019) at 35°C, and the maximum observed change in cycle threshold value per freeze-thaw cycle per day was 0.197 (±0.06). Compared with storage at 4°C, viral RNA levels deviated little but significantly when stored at 25°C or 35°C, or after repeated freeze-thawing. The results of this study indicate that viral RNA levels are relatively stable at higher temperatures and repetitive freeze-thawing.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Specimen Handling
/
RNA, Viral
/
Real-Time Polymerase Chain Reaction
/
COVID-19 Nucleic Acid Testing
/
SARS-CoV-2
/
COVID-19
Type of study:
Diagnostic study
/
Experimental Studies
/
Observational study
Topics:
Long Covid
Limits:
Humans
Country/Region as subject:
Europa
Language:
English
Journal:
J Mol Diagn
Journal subject:
Molecular Biology
Year:
2021
Document Type:
Article
Affiliation country:
J.jmoldx.2021.03.003
Similar
MEDLINE
...
LILACS
LIS