The German Federal Ministry of Education and Research (BMBF) is supporting a research project at the University Hospital of Cologne with more than 400.000 € with the aim to establish a new method for detecting SARS-CoV-2 in smears. The funding is being provided as part of the call for funding for Covid-19 research referring to the SARS-CoV-2 outbreak in March 2020.
Rapid and extensive testing of large parts of the population and specific subgroups is crucial for proper management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and decision-making in times of a pandemic outbreak.
However, point-of-care (POC) testing in places such as emergency units, outpatient clinics, airport security points or the entrance of any public building is a major challenge. The need for thermal cycling and nucleic acid isolation hampers the use of standard PCR-based methods for this purpose. In the current common corona test, ribonucleic acids (RNA) are first purified from smears. These contain the genetic information of the corona virus, which in turn can be multiplied and detected by a real-time polymerase chain reaction (qPCR). The qPCR is rightly regarded as the gold standard, but requires complex analytical equipment and thus usually involves transporting the sample to a special laboratory.
"We focused our work on the development of a fast, inexpensive and, above all, "field-suitable" method that can be used on site without the need for complex laboratory equipment, but can still keep pace with the gold standard in terms of sensitivity and specificity. To avoid these obstacles, we tested PCR-independent methods for the detection of SARS-CoV-2 RNA from primary material (nasopharyngeal swabs) including loop-mediated isothermal amplification (LAMP) and specific high-sensitivity enzymatic reporter unlocking (SHERLOCK)", Prof. Bernhard Schermer comments.
The first results describe a novel multiplexed LAMP approach and validate its sensitivity on primary samples. This approach allows for fast and reliable identification of infected individuals. Primer optimization and multiplexing helps to increase sensitivity significantly.
"In addition, we directly compare and combine our novel LAMP assays with SHERLOCK leading to the conclusion that this reveals a one-step multiplexed LAMP assay as a prime-option for the development of easy and cheap POC test kits", Prof. Schermer states.
The first results of this work have now been made available as preprint in medRxiv(Reprint Server for Health Sciences) with the following title:
Rapid SARS-CoV-2 testing in primary material based on a novel multiplex LAMP assay
Bernhard Schermer, Francesca Fabretti, Maximilian Damagnez, Veronica Di Cristanziano, Eva Heger, Sita Arjune, Nathan A Tanner, Thomas Imhof, Manuel Koch, Alim Ladha, Julia Joung, Jonathan S. Gootenberg, Omar O. Abudayyeh, Volker Burst, Feng Zhang, Florian Klein, Thomas Benzing, Roman-Ulrich Mueller
Prof. Dr. Bernhard Schermer
Dept. for Internal Medicine