Abstract: We constructed a T7 phage display of antigenic variability gene fragment library of bird flu virus. Firstly, we searched and scree
ned the antigenic variability gene of bird flu virus from Gene Bank, truncated, modified and degenerated the gene to obtain the microarray of antigenic variability gene of bird flu virus. Secondly, the recombinant phages DNA were constructed by amplifying and digesting the synthesized antigenic variability gene frament library of bird flu virus and linking it to the T7 phage vector gene. Finally,  T7 phage display library was obtained by packaging and amplification of the recombinant phage DNA in vitro. The titer, recombination rate and immune activity of T7 phase display library were determined. The experimental results show that a total of 96 258 sequences are obtained by searching, screening, cutting and modifying gene bank. T7 phage display library is constructed with original library titer of 3.6×107 colonies/mL. The recombination rate is more than 90%. The bird flu virus H5N1 antibody is used for capture and the ideal target band is obtained and identified by polymerase chain reaction (PCR). The display proteins on the surface of phages have antigenic activities, and can be used for rapid d
etection of bird flu virus infection patients and screening of antigenic epitopes of antibodies.

Key words: T7 phage, phage display, bird flu virus, antigenic variability gene, library identification