Dry Swab Method of sample collection for SARS-CoV2 testing can be used for culturing virus

  1. Sushma Ram
  2. M. Ghalib Enayathullah
  3. Yash Parekh
  4. Karthik Bharadwaj Tallapaka
  5. Rakesh K Mishra
  6. Kiran Kumar Bokara

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

Back ground

Earlier studies suggested the use of dry swab method for SARS-CoV-2 detection as it does not need VTM and subsequent RNA extraction step making the process cheaper, safer and faster. In this study we explore whether the virus in the dry swab is viable and can be cultured and propagated.

Method

Swabs were spiked with SARS-CoV-2 and stored in three different conditions: a) as dry swab (S D , eluted in 1 mL DMEM), b) in 1 mL of Viral Transport Medium (S VTM ), and c) in 1 mL of Tris-EDTA buffer (S TE ). The sample groups were stored either at room temperature (RT, 25°C±1°C) or at 4°C for 1, 4, 8, 12, 24, 48 and 72 hours before being used as viral inoculums for the propagation studies in Vero cells.

Results

The RT-qPCR data suggests that S D incubated both at RT and 4°C harbors viral particles that are viable and culturable at par with S VTM and S TE .

Conclusion

The dry swab method, in addition to its advantages in detection of the virus, also renders viable viral particles that can be cultured and propagated.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2021.03.23.436593: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    2.3 SARS CoV2 Viral Infection: Vero cells seeded in 96-well plates were cultured at 37°C, 5% CO2 in Dulbecco Minimum Essential Medium (DMEM) (Gibco) supplemented with 10% (v/v) Fetal Bovine Serum (FBS) (Gibco), 3.7 g/L sodium bicarbonate.
    Vero
    suggested: None
    Software and Algorithms
    SentencesResources
    Data is represented as mean ± SD using GraphPad Prism 8 (Ver 8.4.2 GraphPad Software, LLC.).
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2021.03.23.436593v1 on bioRxiv