Rapid and convenient detection of SARS-CoV-2 using a colorimetric triple-target reverse transcription loop-mediated isothermal amplification method

Zhu Yang; Nicole Y Liu; Zhiwei Zhu; Minmin Xiao; Shuzhi Zhong; Qiqi Xue; Lina Nie; Jinhong Zhao

doi:10.7717/peerj.14121

Rapid and convenient detection of SARS-CoV-2 using a colorimetric triple-target reverse transcription loop-mediated isothermal amplification method

PeerJ. 2022 Oct 10:10:e14121. doi: 10.7717/peerj.14121. eCollection 2022.

Authors

Zhu Yang^#¹, Nicole Y Liu^#¹, Zhiwei Zhu², Minmin Xiao³, Shuzhi Zhong⁴, Qiqi Xue², Lina Nie³, Jinhong Zhao²

Affiliations

¹ Department of Medical Microbiology and Immunology, Wannan Medical College, Wuhu, Anhui, China.
² Department of Parasitology, Wannan Medical College, Wuhu, Anhui, China.
³ Clinical Laboratory, The Second People's Hospital of Wuhu City, Wuhu, Anhui, China.
⁴ Department of Histology and Embryology, Wannan Medical College, Wuhu, Anhui, China.

^# Contributed equally.

Abstract

Coronavirus Disease 2019 (COVID-19) caused by SARS-CoV-2 poses a significant threat to global public health. Early detection with reliable, fast, and simple assays is crucial to contain the spread of SARS-CoV-2. The real-time reverse transcription-polymerase chain reaction (RT-PCR) assay is currently the gold standard for SARS-CoV-2 detection; however, the reverse transcription loop-mediated isothermal amplification method (RT-LAMP) assay may allow for faster, simpler and cheaper screening of SARS-CoV-2. In this study, the triple-target RT-LAMP assay was first established to simultaneously detect three different target regions (ORF1ab, N and E genes) of SARS-CoV-2. The results revealed that the developed triplex RT-LAMP assay was able to detect down to 11 copies of SARS-CoV-2 RNA per 25 µL reaction, with greater sensitivity than singleplex or duplex RT-LAMP assays. Moreover, two different indicators, hydroxy naphthol blue (HNB) and cresol red, were studied in the colorimetric RT-LAMP assay; our results suggest that both indicators are suitable for RT-LAMP reactions with an obvious color change. In conclusion, our developed triplex colorimetric RT-LAMP assay may be useful for the screening of COVID-19 cases in limited-resource areas.

Keywords: RT-LAMP; Colorimetric; SARS-CoV-2; Triple target.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

COVID-19* / diagnosis
Colorimetry / methods
Humans
RNA, Viral / genetics
Reverse Transcription
SARS-CoV-2* / genetics
Sensitivity and Specificity

Substances

RNA, Viral

Supplementary concepts

LAMP assay

Grants and funding

This research has been supported by grants from Wuhu Science and Technology Plan Project (No. 2020ms3-9, 2021jc2-6 and 2021yf39), Scientific Research Project of Wannan Medical College (No. wyqnyx202004, WK2021Z07 and JXYY202102), Academic Aid Program for Top-Notch Talents in Provincial Universities (No. gxbjZD2020071), Anhui University Natural Science Research Project (No. KJ2020ZD56). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.