TY - JOUR
T1 - Ultrasensitive detection of SARS-CoV-2 spike proteins using the thio-NAD cycling reaction
T2 - A preliminary study before clinical trials
AU - Kyosei, Yuta
AU - Namba, Mayuri
AU - Makioka, Daiki
AU - Kokubun, Ayumi
AU - Watabe, Satoshi
AU - Yoshimura, Teruki
AU - Sasaki, Tadahiro
AU - Shioda, Tatsuo
AU - Ito, Etsuro
N1 - Funding Information:
This research was funded by a Grant-in-Aid for Young Scientists (Early Bird) from the Waseda Research Institute for Science and Engineering, Waseda University to Y.K., a Grant for Joint Research Project of the Research Institute for Microbial Diseases, Osaka University, the A-STEP Program from JST (AS3015096U and JPMJTM20LW) to E.I., and a Grant-in-Aid for Scientific Research (KAKENHI) from JSPS (20H04556) to E.I.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/11
Y1 - 2021/11
N2 - To help control the global pandemic of coronavirus disease 2019 (COVID-19), we developed a diagnostic method targeting the spike protein of the virus that causes the infection, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We applied an ultrasensitive method by combining a sandwich enzyme-linked immunosorbent assay (ELISA) and the thio-nicotinamide adenine dinucleotide (thio-NAD) cycling reaction to quantify spike S1 proteins. The limit of detection (LOD) was 2.62 × 10−19 moles/assay for recombinant S1 proteins and 2.6 × 106 RNA copies/assay for ultraviolet B-inactivated viruses. We have already shown that the ultrasensitive ELISA for nu-cleocapsid proteins can detect ultraviolet B-inactivated viruses at the 104 RNA copies/assay level, whereas the nucleocapsid proteins of SARS-CoV-2 are difficult to distinguish from those in conventional coronaviruses and SARS-CoV. Thus, an antigen test for only the nucleocapsid proteins is insufficient for virus specificity. Therefore, the use of a combination of tests against both spike and nucleocapsid proteins is recommended to increase both the detection sensitivity and testing accuracy of the COVID-19 antigen test. Taken together, our present study, in which we incorporate S1 detection by combining the ultrasensitive ELISA for nucleocapsid proteins, offers an ultrasensitive, antigen-specific test for COVID-19.
AB - To help control the global pandemic of coronavirus disease 2019 (COVID-19), we developed a diagnostic method targeting the spike protein of the virus that causes the infection, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We applied an ultrasensitive method by combining a sandwich enzyme-linked immunosorbent assay (ELISA) and the thio-nicotinamide adenine dinucleotide (thio-NAD) cycling reaction to quantify spike S1 proteins. The limit of detection (LOD) was 2.62 × 10−19 moles/assay for recombinant S1 proteins and 2.6 × 106 RNA copies/assay for ultraviolet B-inactivated viruses. We have already shown that the ultrasensitive ELISA for nu-cleocapsid proteins can detect ultraviolet B-inactivated viruses at the 104 RNA copies/assay level, whereas the nucleocapsid proteins of SARS-CoV-2 are difficult to distinguish from those in conventional coronaviruses and SARS-CoV. Thus, an antigen test for only the nucleocapsid proteins is insufficient for virus specificity. Therefore, the use of a combination of tests against both spike and nucleocapsid proteins is recommended to increase both the detection sensitivity and testing accuracy of the COVID-19 antigen test. Taken together, our present study, in which we incorporate S1 detection by combining the ultrasensitive ELISA for nucleocapsid proteins, offers an ultrasensitive, antigen-specific test for COVID-19.
KW - Antigen test
KW - COVID-19
KW - SARS-CoV-2
KW - Spike protein
KW - Thio-NAD cycling
KW - Ultrasensi-tive ELISA
UR - http://www.scopus.com/inward/record.url?scp=85117963302&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85117963302&partnerID=8YFLogxK
U2 - 10.3390/microorganisms9112214
DO - 10.3390/microorganisms9112214
M3 - Article
AN - SCOPUS:85117963302
SN - 2076-2607
VL - 9
JO - Microorganisms
JF - Microorganisms
IS - 11
M1 - 2214
ER -