TY - JOUR
T1 - Improved detection sensitivity of an antigen test for SARS-CoV-2 nucleocapsid proteins with Thio-NAD cycling
AU - Kyosei, Yuta
AU - Namba, Mayuri
AU - Yamura, Sou
AU - Watabe, Satoshi
AU - Yoshimura, Teruki
AU - Sasaki, Tadahiro
AU - Shioda, Tatsuo
AU - Ito, Etsuro
N1 - Funding Information:
This study was supported by the Grant for Joint Research Project of the Research Institute for Microbial Diseases, Osaka University, the A-STEP Program from JST (AS3015096U and JPMJTM20LW), and the Grant-in-Aid for Scientific Research (KAKENHI) (20H04556).
Publisher Copyright:
© 2021 The Pharmaceutical Society of Japan
PY - 2021/9
Y1 - 2021/9
N2 - Antigen tests for infectious diseases are inexpensive and easy-to-use, but the limit of detection (LOD) is generally higher than that of PCR tests, which are considered the gold standard. In the present study, we combined a sandwich enzyme-linked immunosorbent assay (ELISA) with thionicotinamide-adenine dinucleotide (thio-NAD) cycling to improve the LOD of antigen tests for coronavirus disease 2019 (COVID-19). For recombinant nucleocapsid proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the LOD of our ELISA with thio-NAD cycling was 2.95×10−17 moles/assay. When UV-irradiated inactive SARS-CoV-2 was used, the minimum detectable virions corresponding to 2.6×104 RNA copies/assay were obtained using our ELISA with thio-NAD cycling. The assay volume for each test was 100µL. The minimum detectable value was smaller than that of the latest antigen test using a fluorescent immunoassay for SARS-CoV-2, indicating the validity of our detection system for COVID-19 diagnosis.
AB - Antigen tests for infectious diseases are inexpensive and easy-to-use, but the limit of detection (LOD) is generally higher than that of PCR tests, which are considered the gold standard. In the present study, we combined a sandwich enzyme-linked immunosorbent assay (ELISA) with thionicotinamide-adenine dinucleotide (thio-NAD) cycling to improve the LOD of antigen tests for coronavirus disease 2019 (COVID-19). For recombinant nucleocapsid proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the LOD of our ELISA with thio-NAD cycling was 2.95×10−17 moles/assay. When UV-irradiated inactive SARS-CoV-2 was used, the minimum detectable virions corresponding to 2.6×104 RNA copies/assay were obtained using our ELISA with thio-NAD cycling. The assay volume for each test was 100µL. The minimum detectable value was smaller than that of the latest antigen test using a fluorescent immunoassay for SARS-CoV-2, indicating the validity of our detection system for COVID-19 diagnosis.
KW - Antigen test
KW - Coronavirus disease 2019
KW - Nucleocapsid protein
KW - Severe acute respiratory syndrome coronavirus 2
KW - Thionicotinamide-adenine dinucleotide cycling
KW - Ultrasensitivity
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U2 - 10.1248/bpb.b21-00387
DO - 10.1248/bpb.b21-00387
M3 - Article
C2 - 34148926
AN - SCOPUS:85114102377
SN - 0918-6158
VL - 44
SP - 1332
JO - Biological and Pharmaceutical Bulletin
JF - Biological and Pharmaceutical Bulletin
IS - 9
ER -
