Figure 2
Core particles of bluetongue virus serotype 1 from South Africa (BTV-1 SA), in the final stage of purification, using a self-forming CsCl gradient as described by Mertens et al. (1987). The gradient, which contains approximately 10 mg of BTV-1 SA core particles, was centrifuged in a Beckman SW 40 rotor at 34 Kr.p.m. for 24 h at 277 K. The cores formed only one tight band at a density of 1.40 g cm−3, indicating that they have a single density and therefore have a uniform composition of RNA genome segments and viral proteins. No other contaminating bands were detected. |