A) Double-stranded RNA profile of the virus-containing isolates F11, F12, F13, F18, and a virus-free isolate F7 of S. alkalinus. Viral dsRNAs are marked with arrows. M–DNA size standard. B) Detection of SaFV1 in isolates F13 and F7 by total RNA extraction and Northern blot analysis. Total RNA from virus-containing and virus-free isolates was extracted and resolved by electrophoresis in TAE gel, transferred to a nylon membrane, and probed with specific DIG-labelled probe corresponding nt positions 5026–5412 for SaFV1. The band of about 6.2 kb in size that match the SaFV1 genome size and faint band <4kb indicating the presence of subgenomic RNAs were detected (highlighted by arrows).