Cancer Diagnosis Program | Biorepositories and Biospecimen Research Branch

Search BRD Papers

Evaluation of Transport Media and Specimen Transport Conditions for the Detection of SARS-CoV-2 Using Real Time Reverse Transcription PCR.

Author(s): Rogers AA, Baumann RE, Borillo GA, Kagan RM, Batterman HJ, Galdzicka M, Marlowe EM

Publication: J Clin Microbiol, 2020, Vol. , Page

PubMed ID: 32341141 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to assess the stability of SARS-CoV-2 viral RNA for up to 14 d at ambient, refrigerated, and frozen temperatures in nasopharyngeal/oropharyngeal specimens stored in different transport media, and in bronchoalveolar lavage, and sputum specimens.  A high titer SARS-CoV-2 positive specimen was spiked into corresponding pooled SARS-CoV-2 negative specimens to produce an estimated viral load of 1,500 copies/mL.  SARs-Cov-2 spiked aliquots were subjected to different storage temperatures and tested for viral RNA multiple times during the 14 days of storage.  Viral SARS-CoV-2 RNA stability was also assessed in nasopharyngeal/oropharyngeal swab specimens stored in different transport media (VCM, UTM-RT, ESwab, M4 media, and 0.9% NaCl saline).  Molecular testing was conducted with the QDID SARS-CoV-2 RNA, Qualitative Real-Time RT-PCR EUA assay. A Ct value <40 for both targets was considered SARS-CoV-2 positive (a Ct value of <40 for only one target was considered inconclusive), and stability was defined as a Ct value within 3 cycles of the control analyzed immediately (0 d of storage).  Spiked nasopharyngeal/oropharyngeal swab specimens (diluted to generate a Ct value of 28) stored in saline at ambient, refrigerated, or frozen temperatures over the time course were analyzed at a second site using both the Quest and Roche Cobas SARS-CoV-2 EUA assays.

   Summary of Findings:

   SARS-CoV-2 RNA was detected in all spiked nasopharyngeal/oropharyngeal swab specimens regardless of the transport media used (VCM, UTM-RT, ESwab, M4 media, and 0.9% NaCl saline) for up to 14 d of storage at ambient, refrigerated, or frozen temperatures, and no significant differences were observed between media types or storage temperature and conditions. SARS-CoV-2 RNA was also detected in all spiked bronchoalveolar lavage and sputum specimens and no significant differences were observed between ambient, refrigerated, or frozen storage temperatures for up to 14 d. Ct values obtained with the Quest and Cobas EUAs were strongly correlated (R²= 0.78-0.83) when using spiked nasopharyngeal/oropharyngeal swab specimens stored in saline.  A linear increase in Ct values averaging 0.13-0.15 per day of storage was observed with both assays when swab specimens were stored in saline at ambient or refrigerated temperatures; while Ct values increased by > 2 after 14 d of storage, they were considered stable since the deviation relative to samples processed immediately (0 d of storage) remained ≤ 3 Ct values. 

   Biospecimens

   • Cell - Nasopharynx
   • Bodily Fluid - Bronchial Lavage
   • Cell - Sputum
   • Bodily Fluid - Sputum
   • Bodily Fluid - Nasopharynx

   Preservative Types

   • Other Preservative
   • None (Fresh)

   Diagnoses:

   • Pneumonia/Respiratory Infection

   Platform:

   Analyte	Technology Platform
   RNA	Real-time qRT-PCR

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Short-term storage solution	VCM UTM-RT ESwab M4 media Normal saline (0.9% NaCl)
   Storage	Specimen transport duration/condition	18 to 25°C 2 to 8°C -20 to -30°C 0 d 2 d 3 d 5 d 7 d 10 d 14 d
   Real-time qRT-PCR Specific	Technology platform	Quest EUA Cobas EUA

   View more