Figure 4.

Effect of UV-LED irradiation on viral RNA. Viral suspensions of the H1N1 subtype (strain A/Puerto Rico/8/1934) were irradiated by UV-LEDs or an LP-UV lamp. Viral RNA damage was measured by vRNA (segment 6) strand-specific RT-qPCR, as described in the Materials and Methods section. (a) Damage of viral RNA by each UV irradiation. The dashed line shows the relationship between the peak wavelength and infection ratio. Different letters of the alphabet indicate a statistical difference (p < 0.05) between each other (n = 4–6, n = number of independent replicates). (b) The relationship between the inactivation effects and damage of viral RNA by each UV irradiation. Open circles and the dashed line indicate the data of the infection to MDCK cells. Filled circles and the solid line indicate the infection to embryonated chicken eggs. Viral inactivation effects of these irradiations were indicated by the difference of viral titers (left panels) and the log₁₀ focus-forming assay (FFU) ratio and embryo infection dose (EID₅₀) ratio (right panels), as described in the Materials and Methods section. Results are displayed as means ± SE.