tetano
Editor, Senior Moderator
Viruses
. 2021 Jan 20;13(2):E143.
doi: 10.3390/v13020143.
A 10-Minute "Mix and Read" Antibody Assay for SARS-CoV-2
Juuso Rusanen[SUP] 1 [/SUP], Lauri Kareinen[SUP] 1 2 [/SUP], Lev Levanov[SUP] 1 [/SUP], Sointu Mero[SUP] 3 [/SUP], Sari H Pakkanen[SUP] 3 4 [/SUP], Anu Kantele[SUP] 3 4 [/SUP], Fatima Amanat[SUP] 5 6 [/SUP], Florian Krammer[SUP] 5 [/SUP], Klaus Hedman[SUP] 1 7 [/SUP], Olli Vapalahti[SUP] 1 2 7 [/SUP], Jussi Hepojoki[SUP] 1 8 [/SUP]
Affiliations
Abstract
Accurate and rapid diagnostic tools are needed for management of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Antibody tests enable detection of individuals past the initial phase of infection and help examine vaccine responses. The major targets of human antibody response in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are the spike glycoprotein (SP) and nucleocapsid protein (NP). We have developed a rapid homogenous approach for antibody detection termed LFRET (protein L-based time-resolved F?rster resonance energy transfer immunoassay). In LFRET, fluorophore-labeled protein L and antigen are brought to close proximity by antigen-specific patient immunoglobulins of any isotype, resulting in TR-FRET signal. We set up LFRET assays for antibodies against SP and NP and evaluated their diagnostic performance using a panel of 77 serum/plasma samples from 44 individuals with COVID-19 and 52 negative controls. Moreover, using a previously described SP and a novel NP construct, we set up enzyme linked immunosorbent assays (ELISAs) for antibodies against SARS-CoV-2 SP and NP. We then compared the LFRET assays with these ELISAs and with a SARS-CoV-2 microneutralization test (MNT). We found the LFRET assays to parallel ELISAs in sensitivity (90-95% vs. 90-100%) and specificity (100% vs. 94-100%). In identifying individuals with or without a detectable neutralizing antibody response, LFRET outperformed ELISA in specificity (91-96% vs. 82-87%), while demonstrating an equal sensitivity (98%). In conclusion, this study demonstrates the applicability of LFRET, a 10-min "mix and read" assay, to detection of SARS-CoV-2 antibodies.
Keywords: SARS-CoV-2; TR-FRET; immunoassay; serodiagnosis; serology.
. 2021 Jan 20;13(2):E143.
doi: 10.3390/v13020143.
A 10-Minute "Mix and Read" Antibody Assay for SARS-CoV-2
Juuso Rusanen[SUP] 1 [/SUP], Lauri Kareinen[SUP] 1 2 [/SUP], Lev Levanov[SUP] 1 [/SUP], Sointu Mero[SUP] 3 [/SUP], Sari H Pakkanen[SUP] 3 4 [/SUP], Anu Kantele[SUP] 3 4 [/SUP], Fatima Amanat[SUP] 5 6 [/SUP], Florian Krammer[SUP] 5 [/SUP], Klaus Hedman[SUP] 1 7 [/SUP], Olli Vapalahti[SUP] 1 2 7 [/SUP], Jussi Hepojoki[SUP] 1 8 [/SUP]
Affiliations
- PMID: 33498157
- DOI: 10.3390/v13020143
Abstract
Accurate and rapid diagnostic tools are needed for management of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Antibody tests enable detection of individuals past the initial phase of infection and help examine vaccine responses. The major targets of human antibody response in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are the spike glycoprotein (SP) and nucleocapsid protein (NP). We have developed a rapid homogenous approach for antibody detection termed LFRET (protein L-based time-resolved F?rster resonance energy transfer immunoassay). In LFRET, fluorophore-labeled protein L and antigen are brought to close proximity by antigen-specific patient immunoglobulins of any isotype, resulting in TR-FRET signal. We set up LFRET assays for antibodies against SP and NP and evaluated their diagnostic performance using a panel of 77 serum/plasma samples from 44 individuals with COVID-19 and 52 negative controls. Moreover, using a previously described SP and a novel NP construct, we set up enzyme linked immunosorbent assays (ELISAs) for antibodies against SARS-CoV-2 SP and NP. We then compared the LFRET assays with these ELISAs and with a SARS-CoV-2 microneutralization test (MNT). We found the LFRET assays to parallel ELISAs in sensitivity (90-95% vs. 90-100%) and specificity (100% vs. 94-100%). In identifying individuals with or without a detectable neutralizing antibody response, LFRET outperformed ELISA in specificity (91-96% vs. 82-87%), while demonstrating an equal sensitivity (98%). In conclusion, this study demonstrates the applicability of LFRET, a 10-min "mix and read" assay, to detection of SARS-CoV-2 antibodies.
Keywords: SARS-CoV-2; TR-FRET; immunoassay; serodiagnosis; serology.