Fig. 3

Long-range RT-qPCR to determine IAV infectivity. a Schematic representation of IAV genomic segments, RT-priming sites, and qPCR sites. Common RT primers for segments 1–3 and segments 4–8 are indicated with red and green arrows, respectively. The PCR primers were specific for each segment. b Representative PCR products were visualized by agarose gel electrophoresis to show specificities of the primer pairs. PCR product sizes are 117, 159, 137, 171, 226, 114, and 231 bp for PB2, PA, HA, NP, NA, M, and NS, respectively. MW; Molecular weight marker, NC; No primer control (c) The IAV suspension was irradiated with a UV lamp for increasing periods of time between 15 s to 5 min. IAV copy number was measured by the long-range RT-qPCR assay developed in the present study. Assays were repeated in triplicate and values represent the mean ± standard error (●). The PCR-positive ratio is also plotted on the graph (◆)