Following centrifugation of RV in a CsCl gradient, two distinct, cloudy, whitish-colored bands will be visible. Shining a light on the gradient will facilitate visualization of the bands. The upper band consists of infectious, triple-layered particles (TLPs; density ~1.36 g/cm3) and the lower band consists of non-infectious, double-layered particles (DLPs; density ~1.38 g/cm3). Harvest the upper band as a source of purified RV.