Studies on the particles of infantile gastroenteritis virus (orbivirus group).

Isopycnic centrifugation of infantile gastroenteritis virus (orbivirus group) in a CsCl gradient produced up to four bands at densities 1.38, 1.36, 1.30 and 1.28 g/ml. The particles in the bands had sedimentation coefficients of 380-400S, 520-530S, 270-280S and 320-330S, respectively. Whereas the 1.38 and 1.36 g/ml particles contained RNA, the 1.30 and 1.28 g/ml particles lacked RNA. Upon heating at 37 degrees, the 1.36 g/ml particles broke down into particles of higher and lower density.