FIG. 1.

Purification and characterization of the C. burnetii SCV and LCV. (A) The SCV and LCV of the C. burnetii Nine Mile Crazy variant were separated by equilibrium density centrifugation in 32% cesium chloride (CsCl₂). LCVs (lower band) are denser than SCVs due to their permeability to CsCl₂ (12). (B) Transmission electron micrographs of fractionated SCVs (left panel) and LCVs (right panel) showing the characteristic size and ultrastructure of developmental forms. Bars, 2.0 μm. (C) Confirmation of SCV and LCV fractionation by immunoblotting for ScvA. Shown are a silver-stained polyacrylamide gel of separated SCV (S) and LCV (L) lysates (left panel) and a parallel immunoblot (right panel) probed with polyclonal antiserum to ScvA, an SCV-specific protein (14). Molecular mass markers at the left are expressed in kDa.