The invention provides
a site-directed modification method for
DNA viral
genome, and the problems in the prior art are solved that induction of site-
directed mutagenesis of
DNA viral
genome is difficult, the operation of inserting an exogenous fragment is complex, and
recombination rate is lower. The site-directed modification method comprises: transfecting cells by a
plasmid carrying a
nuclease system, infecting by a
virus, after the cells show
pathological changes, collecting the cells with
pathological changes, performing freeze-thaw or ultrasonic
processing, and centrifuging, separating the liquid supernatant to obtain a progeny
virus. The site-directed modification method is capable of realizing applications to screening of
virus attenuated vaccine strains, construction of viral genetic carriers and an
oncolytic virus, research on virus function sequences, and the like; during modification of the viral
genome, the method helps to improve
mutagenesis efficiency, accurately control
DNA virus for genome site-
directed mutagenesis and specific
gene knockout, simplify operation steps of inserting the
DNA virus carrier by an exogenous
gene, and improve efficiency that the exogenous
gene is integrated to the viral genome, so that the work of screening high-flux recombination viruses is convenient to conduct.