Figure 3From: Differential replication of avian influenza H9N2 viruses in human alveolar epithelial A549 cellsQuantitative analysis of the RNA levels of M1 and PA in A549 cells. (A) A549 cells were infected with H9N2/G1, H9N2/Y280 or H9N2/G9 at an m.o.i. of 2 or mock treated. Total RNA samples of the virus-infected cells were collected at 3 h, 6 h and 24 h post-infection (pi) and assayed by quantitative RT-PCR. The mRNA levels of (A) M1 and (B) PA, normalized to β-actin gene, were compared to the uninfected samples. Mock, uninfected cells; M1, matrix protein; PA, acid polymerase protein.Back to article page