Detection of TULV in MRC5 cells infected with the supernatant from double-infected Vero E6 cells. MRC5 cells were infected with the passage 1 supernatant from Vero E6 cells infected with the mixture of TULV/Lodz and TULV/Moravia. Supernatant was used to infect fresh cells, and from them RNA was isolated. RT-PCR was done with the isolate-specific S- and M-primers. From top: results of RT-PCR assays with the primers specific for: TULV/Lodz S segment, TULV/Lodz M segment, TULV/Moravia S segment, and TULV/Moravia M segment.