Ultrasensitive antigen test for COVID-19


● The PCR method is the definitive diagnosis for COVID-19. However, PCR is technically difficult to perform, time-consuming, and expensive, even though it is a highly sensitive measurement method.
● The global COVID-19 pandemic has increased the demand for accurate, easy-to-use, rapid, and cost-effective ‘antigen tests’ for clinical application. 


● We propose a de novo antigen test for diagnosing COVID-19 using the combination of sandwich ELISA and thio-NAD cycling. Our test takes advantage of the spike (S1) proteins specific to the SARS-CoV-2 virus. 


● A trace amount of S1 protein at 2.3×10-18 moles/assay can be detected using an ultrasensitive ELISA combined with thio-NAD cycling. The thio-NAD cycling  is performed within tens of minutes. 
● The detection sensitivity approaches that of PCR-based assays.


● Our antigen test allows for ultrasensitive measurements of SARS-CoV-2, and has broad application for the diagnosis for COVID-19.
● Our present method is versatile, when we have specific antibodies against the target proteins.


posted: 2020/10/27