Proof of concept of a virus test that combines DNA and antibodies through the utilization of a cell-free protein expression synthesis

Given the current lack of adequate measures to address newly emerging pandemics, the availability of a rapid and accurate testing method during the early stages can significantly enhance our ability to combat the spread of the virus. In this study, our objective is to explore a new protocol for the development of an in vitro test for virus infections, utilizing a combination of nucleic acid and antibody techniques, with the assistance of cell-free protein synthesis (CFPS). In this study, quantitative polymerase chain reaction (qPCR) was employed to amplify 13 virus gene fragments directly from blood samples obtained from a patient with SARS-CoV-2. This was achieved using a set of specifically designed oligonucleotides, which included additional components for transcription, translation, and the incorporation of 6×Hisidine (His6) tags. The linear DNA templates were subsequently transformed into recombinant virus proteins through E.coli based CFPS reactions and then immobilized onto pre-treated 96-well plates. Antibodies obtained from blood samples of a patient were utilized to test the immobilized antigens, serving as serological evidence. The findings indicate that among the 13 antigens tested, the N and Orf10 proteins demonstrate the highest potential as candidates for diagnosing SARS-CoV-2 infection in patients. By investigating the advantages of CFPS, this approach offers a robust tool for the identification of suitable antigens in the early stages of developing immunological test products for future pandemics. Additionally, the utilization of a DNA-antibody coupled test facilitated by CFPS presents novel possibilities in the development of more efficacious detection tools for various pathogens and diseases.