PONE-D-20-37870

Development of a Multiplex Loop-Mediated Isothermal Amplification (LAMP) Assay for On-Site Diagnosis of SARS CoV-2

PLOS ONE

Dear Dr. Lim,

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This manuscript describes (another) development and evaluation of a LAMP assay for Covid19. There are many publications describing such a test (see list below). Consequently the authors should make clear why their test has an add on value.

Although the work is well designed and presented, a concern is that the sample size is rather limited. A sample size calculation is not provided. This must be done.

The paper would stand out amongst all other papers in this particular field if they would have assesses a much larger sample size. This is not the case. Therefore, I recommend that the authors should extend their study population before re-submitting the manuscript.

A non-template control should be included in the assay.

The resolution of figure 2 is rather low.

Loop mediated isothermal amplification (LAMP) assays as a rapid diagnostic for COVID-19.

Kashir J, Yaqinuddin A.Med Hypotheses. 2020 Aug;141:109786. doi: 10.1016/j.mehy.2020.109786. Epub 2020 Apr 25.PMID: 32361529 Free PMC article.

Loop-Mediated Isothermal Amplification (LAMP): A Rapid, Sensitive, Specific, and Cost-Effective Point-of-Care Test for Coronaviruses in the Context of COVID-19 Pandemic.

Augustine R, Hasan A, Das S, Ahmed R, Mori Y, Notomi T, Kevadiya BD, Thakor AS.Biology (Basel). 2020 Jul 22;9(8):182. doi: 10.3390/biology9080182.PMID: 32707972 Free PMC article.

A Rapid, Simple, Inexpensive, and Mobile Colorimetric Assay COVID-19-LAMP for Mass On-Site Screening of COVID-19.

Chow FW, Chan TT, Tam AR, Zhao S, Yao W, Fung J, Cheng FK, Lo GC, Chu S, Aw-Yong KL, Tang JY, Tsang CC, Luk HK, Wong AC, Li KS, Zhu L, He Z, Tam EWT, Chung TW, Wong SCY, Que TL, Fung KS, Lung DC, Wu AK, Hung IF, Woo PC, Lau SK.Int J Mol Sci. 2020 Jul 29;21(15):5380. doi: 10.3390/ijms21155380.PMID: 32751106 Free PMC article.

Rapid Detection of COVID-19 Coronavirus Using a Reverse Transcriptional Loop-Mediated Isothermal Amplification (RT-LAMP) Diagnostic Platform.

Yu L, Wu S, Hao X, Dong X, Mao L, Pelechano V, Chen WH, Yin X.Clin Chem. 2020 Jul 1;66(7):975-977. doi: 10.1093/clinchem/hvaa102.PMID: 32315390 Free PMC article.

RT-LAMP for rapid diagnosis of coronavirus SARS-CoV-2.

Huang WE, Lim B, Hsu CC, Xiong D, Wu W, Yu Y, Jia H, Wang Y, Zeng Y, Ji M, Chang H, Zhang X, Wang H, Cui Z.Microb Biotechnol. 2020 Jul;13(4):950-961. doi: 10.1111/1751-7915.13586. Epub 2020 Apr 25.PMID: 32333644 Free PMC article.

Use of the variplex™ SARS-CoV-2 RT-LAMP as a rapid molecular assay to complement RT-PCR for COVID-19 diagnosis.

Rödel J, Egerer R, Suleyman A, Sommer-Schmid B, Baier M, Henke A, Edel B, Löffler B.J Clin Virol. 2020 Nov;132:104616. doi: 10.1016/j.jcv.2020.104616. Epub 2020 Aug 31.PMID: 32891938 Free PMC article.

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Development of a Multiplex Loop-Mediated Isothermal Amplification (LAMP) Assay for On-Site Diagnosis of SARS CoV-2

PONE-D-20-37870R1

Dear Dr. Lim,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Henk D. F. H. Schallig, Ph.D

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Well revised! Clear sample size estimation and it is noted what the advantage of this approach is compared to other assays

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No