Preparation of nanobody against N protein of SARS-CoV-2 and assembly of colloidal gold immunochromatography card

Autor: Fang-hui WU, Yi-feng YIN, Yan-li LIU
Jazyk: čínština
Rok vydání: 2023
Předmět:
Zdroj: Zhongguo gonggong weisheng, Vol 39, Iss 3, Pp 389-393 (2023)
Druh dokumentu: article
ISSN: 1001-0580
DOI: 10.11847/zgggws1140589
Popis: ObjectiveTo prepare nanobodies against N protein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and apply them to the detection of N protein antigen of SARS-COV-2. MethodsThe alpaca was immunized with N protein to construct a gene library of nanobody to N protein. The nanobody with affinity to N protein was screened with phage display technology; nanobody genes were cloned to yeast plasmids; positive clone strains were picked to induce expression; the secreted proteins were purified with affinity chromatography, desalted with dialysis and concentrated, then screened with enzyme-linked immunosorbent assay (ELISA) for the collection of high affinity nanobodies to N protein. A pair of nanobodies was screened with cross pairing experiment for the preparation of colloidal gold immunochromatography detection cards, and N-protein solution was dropwise added to the sample wells to observe the detection line and quality control line. ResultsTotally 46 nanobodies with different sequences were screened out and 6 of them were selected to express nanobodies with the concentration > 1.0 mg/ml and high affinity to N protein after purification, desalting and enrichment. Finally, the selected pair of antibodies was assembled into colloidal gold N protein immunodetection card to detect N protein with sandwich method. Obvious detection line and quality control line were observed in the test of SARS-CoV-2 N protein antigen using the detection card and the detection limit was ≥ 10 μg/mL for the test. ConclusionThe prepared nanobody can be used in the colloidal gold nanobody immunochromatography detection card to detect SARS-CoV-2 N protein.
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