Fig. 2

Identification of the 3A mutant viruses by RT-PCR. HN-1F/HN-4R was used to confirm the presence of the engineered deletions with the expected size in the mutant viruses. The detection of r/HN/3A77–153, r/HN/3A76I-153, r/HN/3A76V-153, r/HN/3A80–153 and r/HN viruses are shown in lanes 1, 2, 3, 4 and 5, respectively, M refers to a 2000 bp DNA ladder (Takara Biolabs)