Abstract
Background: Viral antigen detection test is the most common method used to detect viruses in the field rapidly. However, due to the low sensitivity, it can only be used as an auxiliary diagnosis method for virus infection. Improving sensitivity is crucial for developing more accurate viral antigen tests. Nano luciferase (Nluc) is a sensitive reporter that has not been used in virus detection.
Results: In this study, we produced an intracellularly Nluc labeled detection antibody (Nluc-ch2C5) and evaluated its ability to improve the detection sensitivity of respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens. Compared with the traditional horse-radish peroxidase (HRP) labeled antibody (HRP-ch2C5), Nluc-ch2C5 was 41 times more sensitive for inactivated SARS-CoV-2 virus by sandwich chemiluminescence ELISA. Then we applied Nluc-ch2C5 to establish an automatic magnet chemiluminescence immune assay (AMCA) for the SARS-CoV-2 viral spike protein, the limit of detection was 68 pfu/reaction. The clinical sensitivity and specificity reached 75% (24/32) and 100% (48/48) using 32 PCR-positive and 48 PCR-negative swab samples for clinical evaluation, which is more sensitive than the commercial ELSA kit and colloid gold strip kit.
Conclusions: Here, monoclonal antibody ch2C5 served as a model antibody and the SARS-CoV-2 served as a model pathogen. The Nluc labeled detecting antibody (Nluc-ch2C5) significantly improved the detection sensitivity of SARS-CoV-2 antigen. This labeling principle applies to other viral infections, so this labeling and test format could be expected to play an important role in detecting other virus antigens.
Keywords: Antigen detection; Automatic magnet chemiluminescence immune assay (AMCA); Highly sensitive; Nano luciferase; SARS-CoV-2.
【저자키워드】 SARS-CoV-2., nano luciferase, Highly sensitive, antigen detection, Automatic magnet chemiluminescence immune assay (AMCA), 【초록키워드】 SARS-CoV-2, antibody, monoclonal antibody, Diagnosis, SARS-CoV-2 virus, viral infections, respiratory syndrome coronavirus 2, ELISA, immune, Spike protein, sensitivity, specificity, pathogen, clinical evaluation, virus detection, limit of detection, gold, antigens, virus infection, SARS-CoV-2 antigen, reporter, antigen detection, chemiluminescence, inactivated, Detection sensitivity, clinical sensitivity, peroxidase, viral spike protein, Viral antigen, PCR-positive, swab samples, respiratory syndrome coronavirus, nLuc, PCR-negative, luciferase, labeling, detection antibody, virus antigens, labeled antibody, swab sample, IMPROVE, produced, detect, virus, significantly, evaluated, applied, reached, expected, Automatic, auxiliary, HRP, Improving, the SARS-CoV-2, 【제목키워드】 antibody, Viral antigen, preparation,