1. Low saliva pH can yield false positives results in simple RT-LAMP-based SARS-CoV-2 diagnostic tests
- Author
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Jonathan Chernoff, Don A. Baldwin, Cristina Uribe-Alvarez, and Quynh Lam
- Subjects
0301 basic medicine ,RNA viruses ,Saliva ,Viral Diseases ,Coronaviruses ,Physiology ,Oligonucleotides ,Biochemistry ,Purification techniques ,0302 clinical medicine ,Medical Conditions ,Limit of Detection ,Nasopharynx ,False positive paradox ,Medicine ,Chemical Precipitation ,030212 general & internal medicine ,Pathology and laboratory medicine ,Virus Testing ,Multidisciplinary ,Nucleotides ,Chemical Reactions ,Hydrogen-Ion Concentration ,Medical microbiology ,Body Fluids ,Precipitation Techniques ,Chemistry ,Infectious Diseases ,Molecular Diagnostic Techniques ,RNA purification ,Viruses ,Physical Sciences ,RNA, Viral ,RNA extraction ,Sample collection ,SARS CoV 2 ,Pathogens ,Anatomy ,Nucleic Acid Amplification Techniques ,Research Article ,SARS coronavirus ,Science ,Sensitivity and Specificity ,Microbiology ,03 medical and health sciences ,Diagnostic Medicine ,Humans ,False Positive Reactions ,Detection limit ,Medicine and health sciences ,Biology and life sciences ,business.industry ,SARS-CoV-2 ,Organisms ,Viral pathogens ,COVID-19 ,Covid 19 ,Nucleic acid amplification technique ,Virology ,Microbial pathogens ,Research and analysis methods ,030104 developmental biology ,Infectious disease (medical specialty) ,Nucleic acid ,business - Abstract
Diagnosis of any infectious disease is vital for opportune treatment and to prevent dissemination. RT-qPCR tests for detection of SARS-CoV-2, the causative agent for COVID-19, are ideal in a hospital environment. However, mass testing requires cheaper and simpler tests, especially in settings that lack sophisticated machinery. The most common current diagnostic method is based on nasopharyngeal sample collection, RNA extraction, and RT-qPCR for amplification and detection of viral nucleic acids. Here, we show that samples obtained from nasopharyngeal swabs in VTM and in saliva can be used with or without RNA purification in an isothermal loop-mediated amplification (LAMP)-based assay, with 60โ93% sensitivity for SARS-CoV-2 detection as compared to standard RT-qPCR tests. A series of simple modifications to standard RT-LAMP published methods to stabilize pH fluctuations due to salivary acidity resulted in a significant improvement in reliability, opening new avenues for efficient, low-cost testing of COVID-19 infection.
- Published
- 2020