First-of-Its-Kind Saliva-Based Rapid Test Uses DNA Aptamer to Detect COVID-19

As the world moves beyond the acute phase of the pandemic amidst the slow rate of vaccination in developing countries, the combination of ultra-low cost, highly accurate testing and rising availability of therapeutics may present an option to alleviate the effects of COVID-19 for the vast majority of people so that everyone can continue with their daily lives. Now, a newly-launched affordable, saliva-based rapid test uses a DNA aptamer instead of an antibody to detect COVID-19 and is read by a UV Spectrophotometer. DNA aptamers are believed to offer a structural advantage over other enzyme-based approaches in sensitivity, specificity, quality of production, lower costs, test formats and other areas.

The AptameX COVID-19 rapid test from Achiko AG (Zurich, Switzerland) is an innovative rapid test that uses DNA aptamers instead of antigens to detect the SARS-CoV-2 virus. Aptamers are single-stranded DNA or RNA oligonucleotides that bind to specific targets via shape recognition with high affinity and specificity. As aptamers are synthetic, they can be produced at a low cost and in scale. By using aptamer technology, the company has been able to design a friendlier and better customer experience that achieves higher degrees of accuracy than nearly all other rapid tests and at a lower cost to the end consumer.

Image: AptameX DNA Aptamer-based COVID-19 rapid test has received CE Mark (Photo courtesy of Achiko)

The AptameX COVID-19 rapid test comes in the form of a user-friendly, saliva-based rapid test. First, a patient rinses their mouth with a standard non-alcoholic dental mouthwash, followed by purified water. The patient then spits into a sample collection tube which is then processed by a lab. The sample is diluted in water and added to a cuvette containing reagent. After 10 minutes, a salt quench is added and after one minute, the sample is ready to be scanned by a standard UV-spectrophotometer. The rapid test is separated into the sampling and software, plus the spectrophotometer. Future iterations may be packaged with other approved spectrophotometers to provide a more convenient solution.

Through differentiated chemistry, Achiko has been able to develop a user-friendly, saliva-based test that is sensitive at the important higher CT values. In a clinical environment, the company had successfully classified results when compared against a PCR test, at above 97% sensitivity and 97% specificity at an average CT score of 28, substantially higher than what many rapid tests are reporting. Achiko has successfully registered AptameX under the European Union’s Medical Device Research (MDR) and In Vitro Diagnostic Regulation (IVDR), and has obtained a CE Mark that grants it access to 27 countries in the European Union for its COVID-19 AptameX test and system, establishing a foundation for applying for regulatory approval across the world.

“This is the first major mainstream use of DNA aptamers in a consumer testing product and a fantastic milestone for Achiko,” stated Steven Goh, CEO of Achiko AG. “This matters as the world moves to treating COVID-19 as endemic, key sectors such as aged care, healthcare, manufacturing, and many others need to find a way to cope with COVID’s challenges. PCR testing whilst accurate is often impractical in an endemic setting, and recent research indicates that many rapid tests are simply not sensitive enough to detect the more recent variants.”

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Achiko AG