tetano
Editor, Senior Moderator
Microorganisms
. 2021 Oct 25;9(11):2214.
doi: 10.3390/microorganisms9112214.
Ultrasensitive Detection of SARS-CoV-2 Spike Proteins Using the Thio-NAD Cycling Reaction: A Preliminary Study before Clinical Trials
Yuta Kyosei[SUP] 1 [/SUP], Mayuri Namba[SUP] 1 [/SUP], Daiki Makioka[SUP] 1 [/SUP], Ayumi Kokubun[SUP] 1 [/SUP], Satoshi Watabe[SUP] 2 [/SUP], Teruki Yoshimura[SUP] 3 [/SUP], Tadahiro Sasaki[SUP] 4 [/SUP], Tatsuo Shioda[SUP] 4 [/SUP], Etsuro Ito[SUP] 1 2 5 [/SUP]
Affiliations
Abstract
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[SUP]-19[/SUP] moles/assay for recombinant S1 proteins and 2.6 × 10[SUP]6[/SUP] RNA copies/assay for ultraviolet B-inactivated viruses. We have already shown that the ultrasensitive ELISA for nucleocapsid proteins can detect ultraviolet B-inactivated viruses at the 10[SUP]4[/SUP] 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.
Keywords: COVID-19; SARS-CoV-2; antigen test; spike protein; thio-NAD cycling; ultrasensitive ELISA.
. 2021 Oct 25;9(11):2214.
doi: 10.3390/microorganisms9112214.
Ultrasensitive Detection of SARS-CoV-2 Spike Proteins Using the Thio-NAD Cycling Reaction: A Preliminary Study before Clinical Trials
Yuta Kyosei[SUP] 1 [/SUP], Mayuri Namba[SUP] 1 [/SUP], Daiki Makioka[SUP] 1 [/SUP], Ayumi Kokubun[SUP] 1 [/SUP], Satoshi Watabe[SUP] 2 [/SUP], Teruki Yoshimura[SUP] 3 [/SUP], Tadahiro Sasaki[SUP] 4 [/SUP], Tatsuo Shioda[SUP] 4 [/SUP], Etsuro Ito[SUP] 1 2 5 [/SUP]
Affiliations
- PMID: 34835340
- DOI: 10.3390/microorganisms9112214
Abstract
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[SUP]-19[/SUP] moles/assay for recombinant S1 proteins and 2.6 × 10[SUP]6[/SUP] RNA copies/assay for ultraviolet B-inactivated viruses. We have already shown that the ultrasensitive ELISA for nucleocapsid proteins can detect ultraviolet B-inactivated viruses at the 10[SUP]4[/SUP] 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.
Keywords: COVID-19; SARS-CoV-2; antigen test; spike protein; thio-NAD cycling; ultrasensitive ELISA.