{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:56:12Z","timestamp":1760147772877,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,2,27]],"date-time":"2023-02-27T00:00:00Z","timestamp":1677456000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Antibodies against the SARS-CoV-2 nucleocapsid protein are produced by the immune system in response to SARS-CoV-2 infection, but most available vaccines developed to fight the pandemic spread target the SARS-CoV-2 spike protein. The aim of this study was to improve the detection of antibodies against the SARS-CoV-2 nucleocapsid by providing a simple and robust method applicable to a large population. For this purpose, we developed a DELFIA immunoassay on dried blood spots (DBSs) by converting a commercially available IVD ELISA assay. A total of forty-seven paired plasma and dried blood spots were collected from vaccinated and\/or previously SARS-CoV-2-infected subjects. The DBS-DELFIA resulted in a wider dynamic range and higher sensitivity for detecting antibodies against the SARS-CoV-2 nucleocapsid. Moreover, the DBS-DELFIA showed a good total intra-assay coefficient of variability of 14.6%. Finally, a strong correlation was found between SARS-CoV-2 nucleocapsid antibodies detected by the DBS-DELFIA and ELISA immunoassays (r = 0.9). Therefore, the association of dried blood sampling with DELFIA technology may provide an easier, minimally invasive, and accurate measurement of SARS-CoV-2 nucleocapsid antibodies in previously SARS-CoV-2-infected subjects. In conclusion, these results justify further research to develop a certified IVD DBS-DELFIA assay for detecting SARS-CoV-2 nucleocapsid antibodies useful for diagnostics as well as for serosurveillance studies.<\/jats:p>","DOI":"10.3390\/diagnostics13050897","type":"journal-article","created":{"date-parts":[[2023,2,27]],"date-time":"2023-02-27T04:13:16Z","timestamp":1677471196000},"page":"897","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Development of a Method for Detection of SARS-CoV-2 Nucleocapsid Antibodies on Dried Blood Spot by DELFIA Immunoassay"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2833-841X","authenticated-orcid":false,"given":"Verena","family":"Damiani","sequence":"first","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erika","family":"Pizzinato","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9792-2225","authenticated-orcid":false,"given":"Ilaria","family":"Cicalini","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gianmaria","family":"Demattia","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mirco","family":"Zucchelli","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luca","family":"Natale","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claudia","family":"Palmarini","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claudia","family":"Di Marzio","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luca","family":"Federici","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vincenzo","family":"De Laurenzi","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1015-3484","authenticated-orcid":false,"given":"Damiana","family":"Pieragostino","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Innovative Technologies in Medicine and Dentistry, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/j.jiph.2022.11.024","article-title":"Global emerging Omicron variant of SARS-CoV-2: Impacts, challenges and strategies","volume":"16","author":"Dhama","year":"2023","journal-title":"J. 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