Fig. 4.

Rescue efficiency of pHW2000 and pDK2022 systems using avian influenza viruses. A set of pHW2000 and pDK2022 plasmids containing eight segments of (A) H1731, (B) H1924, and (C) H2102 were transfected into 293T and DF-1, respectively. After 48 h post-infection, the growth media supernatant was collected and inoculated into embryonated eggs for the propagation of recombinant viruses. Subsequently, allantoic fluid was harvested from the eggs, and the viruses were titered using a hemagglutination assay. Data representing individual rescue trials are presented as mean titers of log2 HA units ±standard deviation.