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A Smartphone Based in-Gel Loop Mediated Isothermal Amplification (gLAMP) System Enables Rapid Coliphage MS2 Quantification in Environmental Waters

Huang, Xiao and Lin, Xingyu and Urmann, Katharina and Li, Lijie and Xie, Xing and Jiang, Sunny and Hoffmann, Michael R. (2018) A Smartphone Based in-Gel Loop Mediated Isothermal Amplification (gLAMP) System Enables Rapid Coliphage MS2 Quantification in Environmental Waters. Environmental Science and Technology, 52 (11). pp. 6399-6407. ISSN 0013-936X. PMCID PMC5990930.

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Model coliphages (e.g., ΦX174, MS2, and PRD1) have been widely used as surrogates to study the fate and transport of pathogenic viruses in the environment and during wastewater treatment. Two groups of coliphages (F-specific and somatic) are being explored as indicators of viral fecal pollution in ambient water. However, the detection and quantification of coliphages still largely rely on time-consuming culture-based plaque assays. In this study, we developed an in-gel loop-mediated isothermal amplification (gLAMP) system enabling coliphage MS2 quantification within 30 min using standard laboratory devices. Viral particles (MS2) were immobilized with LAMP reagents in polyethylene glycol hydrogel, and then viral RNAs were amplified through a LAMP reaction. Due to the restriction effect of the hydrogel matrix, one viral particle would only produce one amplicon dot. Therefore, the sample virus concentrations can be determined based on the number of fluorescent amplicon dots using a smartphone for imaging. The method was validated by using artificially spiked and naturally contaminated water samples. gLAMP results were shown to correlate well with plaque assay counts (R^2 = 0.984, p < 0.05) and achieved similar sensitivity to quantitative reverse-transcription polymerase chain reaction (RT-qPCR; 1 plaque-forming unit per reaction). Moreover, gLAMP demonstrated a high level of tolerance against inhibitors naturally present in wastewater, in which RT-qPCR was completely inhibited. Besides MS2, gLAMP can also be used for the quantification of other microbial targets (e.g., Escherichia coli and Salmonella). Considering its simplicity, sensitivity, rapidity, and versatility, gLAMP holds great potential for microbial water-quality analysis, especially in resource-limited settings.

Item Type:Article
Related URLs:
URLURL TypeDescription Information CentralArticle
Huang, Xiao0000-0002-3737-6939
Lin, Xingyu0000-0002-0950-0736
Li, Lijie0000-0002-7988-6208
Xie, Xing0000-0002-2253-0964
Jiang, Sunny0000-0002-4993-8038
Hoffmann, Michael R.0000-0001-6495-1946
Additional Information:© 2018 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. Received: January 13, 2018; Revised: April 12, 2018; Accepted: May 8, 2018; Published: May 8, 2018. The authors acknowledge the financial support provided by the Bill and Melinda Gates Foundation (grant no. OPP1111252). The authors declare no competing financial interest.
Funding AgencyGrant Number
Bill and Melinda Gates FoundationOPP1111252
Issue or Number:11
PubMed Central ID:PMC5990930
Record Number:CaltechAUTHORS:20180508-134902216
Persistent URL:
Official Citation:Smartphone-Based in-Gel Loop-Mediated Isothermal Amplification (gLAMP) System Enables Rapid Coliphage MS2 Quantification in Environmental Waters. Xiao Huang, Xingyu Lin, Katharina Urmann, Lijie Li, Xing Xie, Sunny Jiang, and Michael R. Hoffmann. Environmental Science & Technology 2018 52 (11), 6399-6407 DOI: 10.1021/acs.est.8b00241
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86286
Deposited By: Tony Diaz
Deposited On:08 May 2018 21:33
Last Modified:09 Mar 2020 13:19

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