title: Purification of hepatitis B antigen associated particles: use of a reorienting gradient rotor.
mesh_terms: D002499:Centrifugation, Density Gradient / Q000295:instrumentation*; D006511:Hepatitis B Antigens / Q000302:isolation & purification*; D008722:Methods; D008854:Microscopy, Electron
chemical_list: D006511:Hepatitis B Antigens