Characterisation of rubella virus hemagglutinin rosettes

Purified rubella virus treated with Triton X-100 was subjected to centrifugation in a sucrose density gradient containing nonionic detergent beta-D-octylglucoside. The result of this treatment was the formation of hemagglutinating rosettes containing viral glycoproteins VP2 (50,000 mol. wt.) and VP3 (63,000 mol. wt.). The rosettes have a 26 S sedimentation coefficient and a density of 1.2 g/cm3 in sucrose. Electron microscopy revealed 15 nm rosettes with a hollow center. The molecular weight of the rosettes was extrapolated at 850,000.