RESUMEN
Expression and purification of different fragments of the new coronavirus nucleocapsid (N) protein, establish a new coronavirus total antibody fluorescence immunochromatographic method and evaluate the influence of different protein fragments on the method. Using bioinformatics technology to analyze, synthesize, express and purify the N protein sequence, prepare different N protein fragments;use 1-ethyl-(3-dimethylaminopropyl) carbodiimide (1-( 3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) method of fluorescent microspheres coupled with antigen was established to establish a sandwich fluorescence chromatography antibody detection method, and the performance was evaluated respectively. In the prepared 4 N protein fragments, the full-length N protein (N419) is preferably coated, and N412 is labeled with 0.5mol/L NaCl as the optimal combination;the 91-120th amino acid (N412) of the N-terminus of the N antigen is deleted It can reduce 87.5% of non-specific interference;the linear range is 0.312-80U/L, the lowest detection limit is 0.165U/L, and the accuracy is above 95%. The fluorescence immunochromatographic detection method for total antibodies of the new coronavirus established by pairing the N protein fragments has a total coincidence rate of 98% compared with the Guangzhou Wanfu test strip. The improvement provides experimental basis and reference.