Abstract: ObjectiveIn this work,the anti-aflatoxin B1(AFB1)single chain antibody(scFv)gene was constructed, and its encoded protein sequence and structure was analyzed and predicted,which provided reference for scFv molecular modification and application in immunological detection.MethodIn this study,anti-AFB1 hybridoma cell strains were used as materials,the variable region of heavy chain(VH)and light chain(VL)were amplified by PCR,then anti-AFB1 gene scFv was built with(Gly4Ser)3 as flexible joint(Linker). The amino acid sequence,its physicochemical properties and protein structure were analyzed by online bioinformatics analysis software.ResultThe results indicated that the full anti-AFB1 gene scFv was 744 bp in length,encoding 248 amino acids. The molecular weight was 26312.05 Da,and theoretical isoelectric point(pI)5.70. In secondary structure,there were 35α-helixes(14.11%),28β-folds(11.29%),85 extended strands(34.28%)and 100 random coils(40.32%). In tertiary structure,connective peptides pulled together VH and VL to form a typical abtibidu structure—groove structure,which was the antigen binding region for scFv.Conclu-sionThe constructed anti-AFB1 scFv VH contain 117 amino acids and VL contained 116 amino acids with a typical antibody structure—groove structure,which can combine with antigen specificity.