Laboratory-Generated DNA Can Cause Anomalous Pathogen Diagnostic Test Results

Abstract

To meet the challenges imposed by the COVID-19 pandemic, research laboratories shifted their focus and clinical diagnostic laboratories developed and utilized new assays. Nucleic acid-based testing became widespread and, for the first time, was used as a prophylactic measure.

Persistent Nonviral Plasmid Vector in Nasal Tissues Causes False-Positive SARS-CoV-2 Diagnostic Nucleic Acid Tests

“…Unlike prior reports of false diagnostic test results due to contamination of specimens by PCR amplicons ( 2 , 3 ), the nasal specimens from the individuals we studied remained positive over days to weeks, including when the individuals were in isolation in their homes. The prolonged detection of SARS-CoV-2 nucleocapsid plasmid DNA from longitudinally collected nasal swabs suggests that the plasmid was present in their nasal tissues or that the Escherichia coli containing the plasmid had colonized their noses.…”

“…Plasmid vectors, commonly used in research, can contaminate laboratory reagents ( 7 ) and biological samples ( 8 ), leading to false scientific claims ( 8 , 9 ) or diagnostic results ( 2 – 4 ), which can create emotional stress for patients and divert health care resources to further tests. While plasmids are regarded as safe laboratory reagents, personnel handling plasmid solutions should use PPE and dedicated laboratory areas physically separated from spaces used for sample collection, processing, or nucleic acid amplification.…”

Comparison of Biosensing Methods Based on Different Isothermal Amplification Strategies: A Case Study with Erwinia amylovora

“…For LAMP-LFT and LAMP-CRISPR/Cas, the analysis time was 40 and 55 min, respectively; a 37 and 60 °C heaters (LAMP-LFT, LAMP-CRISPR/Cas) and a simple fluorescent detector (LAMP-CRISPR/Cas) were required. In addition, it is important to consider that LAMP-LFT or LAMP-CRISPR/Cas, with the detection method involving open-tubes techniques, very often provide false positive results caused by carryover contamination [ 54 , 55 ]. This shortcoming can be prevented by implementing closed-tube detection devices or carefully separated places for sample preparation and for analysis [ 56 , 57 , 58 ].…”

Promise and perils of paper-based point-of-care nucleic acid detection for endemic and pandemic pathogens

“…Due to their exquisite sensitivity, precautions preventing nucleic acid crosscontamination are of utmost importance. These are wellknown challenges in the research laboratory and have been highlighted by recent COVID-19 shifts in research, [75][76][77] but additional precautions are required when designed for layusers who cannot be expected to be experts in molecular technologies. Existing paper tests such as LFIAs, colorimetric tests, often include results that are open to the environment and can spread cross-contamination of amplicons leading to future tests with false positive results if not properly handled.…”