Purification and ultrastructural analysis of occlusion bodies derived from wild type and recombinant viruses infected insects. AcMNPV polyhedra (Polh) and Polh-6xHis and Polh-GarMbFV-CP-6xHis crystals from infected S. frugiperda cadavers were purified by centrifugation through a sucrose gradient. (A) A centrifuge tube after centrifugation of vAc-polh-GarMbFV-cp-6xHis-infected insect extracts showing a lower band containing the putative crystals. The upper band shows the fat fraction from the insect cadavers. (B) The crystals were collected from the gradient and prepared for scanning electron microscopy: (I) Occlusion bodies from wild type AcMNPV infected insect cadavers; (II) Occlusion bodies from vAc-polh-6xhis-infected insect cadavers showing a triangular shaped crystal; and (III) Occlusion bodies-like from vAc-polh-GarMbFV-cp-6xhis-infected insect cadavers showing some crystals and undefined mass protein of Polh-GarMbFV-CP-6xHis (Scale bar = 5 μm).