{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T13:10:58Z","timestamp":1776258658560,"version":"3.50.1"},"reference-count":0,"publisher":"Knowledge E DMCC","content-domain":{"domain":["kne-publishing.com","knepublishing.com","ajmb.org"],"crossmark-restriction":true},"short-container-title":["AJMB"],"abstract":"<jats:p>Background: SARS-CoV-2 is a novel coronavirus that has caused dramatic loss of life and poses an unprecedented public health challenge worldwide. The nucleocapsid (N) protein of SARS-CoV-2 is the most abundant viral protein and a potent immunogen.\r\nMethods: In the current study, the N gene of SARS-CoV-2 was amplified from RNA extracted from a COVID-19 positive patient and then cloned into the pCold-I expression vector. The full-length His-tagged N protein was expressed in Escherichia coli (E. coli) using 0.5 mM IPTG and subsequently purified by nickel affinity chromatography. The purified N protein was characterized using sodium dodecyl sulfate\u2013polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Furthermore, the purified N protein was applied in SARS-CoV-2 IgG and IgM ELISA immunoassays.\r\nResults: The results showed that purification of the N protein in the presence of urea yielded a protein band of approximately 48 kDa on SDS-PAGE, corresponding to the full-length N protein. Additionally, Western blot analysis of the purified recombinant N protein showed a band of the same molecular weight. In the SARS-CoV-2 IgG ELISA assay, anti-N protein antibodies from a COVID-19 positive patient\u2019s serum successfully recognized the coated N protein. In the IgM ELISA test, an N-HRP conjugate was used in ELISA wells to reveal the interaction of HRP-conjugated N protein with pre-coated anti-N protein antibodies (IgM isotype).\r\nConclusion: These results indicate that the expressed N protein of SARS-CoV-2 could serve as a valuable reagent for the development of antibody-based immunoassays to detect SARS-CoV-2 IgG and IgM antibodies.<\/jats:p>","DOI":"10.18502\/ajmb.v18i1.21046","type":"journal-article","created":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T08:19:11Z","timestamp":1771316351000},"update-policy":"https:\/\/doi.org\/10.18502\/knecrossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Expression, Purification, and Application of SARS-CoV-2 Nucleocapsid Protein for  Serological Detection of IgG and IgM Antibodies"],"prefix":"10.18502","author":[{"given":"Saeideh Zamani","family":"Koukhaloo","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Farshid","family":"Moosavi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bahareh","family":"Zamani","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Niloofar","family":"Agharezaee","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Parisa","family":"Yousefi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mahboobeh","family":"Nazari","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jafar","family":"Mahmoudian","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"7770","published-online":{"date-parts":[[2026,2,17]]},"container-title":["Avicenna Journal of Medical Biotechnology"],"original-title":[],"deposited":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T12:09:53Z","timestamp":1776254993000},"score":1,"resource":{"primary":{"URL":"https:\/\/publish.kne-publishing.com\/index.php\/AJMB\/article\/view\/21046"},"secondary":[{"URL":"https:\/\/www.ajmb.org\/Article.aspx?id=70638","label":"UNIVERSITY"}]},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,17]]},"references-count":0,"URL":"https:\/\/doi.org\/10.18502\/ajmb.v18i1.21046","relation":{},"ISSN":["2008-4625","2008-2835"],"issn-type":[{"value":"2008-4625","type":"electronic"},{"value":"2008-2835","type":"print"}],"subject":[],"published":{"date-parts":[[2026,2,17]]}}}