Doha: Sidra Medicine, a member of Qatar Foundation, has developed a simplified and rapid, second COVID-19 testing method. The new method uses a pre-treatment of the specimen (swab sample) to replace the ribonucleic acid (RNA) extraction process, currently needed for COVID-19 testing.
Current methods for testing COVID-19 follow a three-step process – starting with obtaining a swab sample from an individual; followed by extraction of viral RNA from the sample; and then detecting the viral RNA specific to COVID-19 by reverse transcription polymerase chain reaction (RT-PCR). The whole process can take between four to six hours from the time the swab is received in the lab to the time results are reported.
The new method developed in-house at Sidra Medicine’s pathology laboratory, which is accredited by the College of American Pathologists (CAP), replaces the viral RNA extraction process by simple dilution with nuclease-free water (purified water to remove enzymes that may degrade DNA and RNA) and heat treatment. The diluted sample is treated at 65oC for 10 minutes before detection of viral RNA using a specific type of RT-PCR reagent.
Following guidelines from the Clinical Laboratory Improvements Act (CLIA), the alternative test method has been validated in the Pathology Department of Sidra Medicine. It produces a faster result than current methods and demonstrates 98 per cent accuracy, compared to the standard method that requires RNA extraction. As the RNA extraction process constitutes a significant part of the cost and time involved in COVID-19 testing, the alternative method, which is significantly cheaper, will be particularly useful for resource-limited countries for expanding their capacity for COVID-19 testing.
The new method was developed by Dr Mohammad Rubayet Hasan, a clinical molecular microbiologist in collaboration with a team of technologists and research associates from the Molecular Infectious Diseases (MID) Lab at Sidra Medicine. The program is being overseen by Dr. Patrick Tang, the Division Chief of Pathology Sciences.
Dr Hasan said: “Many organizations globally, including Sidra Medicine have invested in ground-breaking technologies and developed advanced protocols to test for COVID-19. Our use of automated RNA extraction platforms and liquid handling robots, have proven their merit for large volume testing. However, we wanted to have an additional alternative should the reagents for RNA extraction become limited.”
“In addition, several of the resources that are currently being used, are absent or scarce in developing countries. Therefore, our direct approach, using the pre-treatment process and negating the need for the viral RNA extraction, would help expand the capacity to test for COVID-19. It is also easy to implement as it does not need any special equipment, materials or skill,” continued Dr. Hasan.
By skipping the RNA extraction step and replacing it with a simple pre-treatment process, the new method will reduce the cost of the test by approximately 75 per cent and will also improve the turn-around time of the test by approximately two hours.
Dr Tang said: “We developed this method as part of a mitigation and preparation plan against the global shortage of critical reagents needed for COVID-19 testing. It is available as an alternative in case of equipment or supply chain failures. Also it relies on equipment that is readily available in most laboratories - a heating block and nuclease-free water.”
“While we are currently using another in-house developed process to test for COVID-19 here at Sidra Medicine, it is reassuring that our scientists and technologists are working on innovative and cost-efficient ways to ensure that we have back-up plans that reduce our dependencies on equipment and reagents that are in short supply outside Qatar. I am also proud to showcase that our team in Qatar is working on solutions that can address global issues especially for countries that have limited resources,” concluded Dr. Tang.
The alternative method is available as a pre-print in the health science publication medRxiv (https://www.medrxiv.org/content/10.1101/2020.04.18.20070755v2) and is under peer review in an academic journal.
The new method is the second one to be developed in-house at Sidra Medicine, following the success of the first method using a different RNA extraction process with alternative test components.
Sidra Medicine is not a COVID-19 designated hospital and does not treat COVID-19 patients. For any inquiries regarding COVID-19, call Qatar’s Ministry of Public Health hotline: 16000.