Adenovirus of ring-necked pheasants: purification and partial characterization of marble spleen disease virus.

A method for purification of marble spleen disease virus (MSDV) from the spleens of infected turkeys and pheasants is described. It combines chloroform or fluorocarbon extraction with subsequent purification by centrifugation on a cushion of cesium chloride (CsCl). Further purification of MSDV was accomplished with a CsCl equilibrium density gradient. A viral buoyant density of approximately 1.32 to 1.33 g/cm3 was determined. Negative-stain electron microscopy revealed that virus isopycnically banded by CsCl gradient had non-enveloped icosahedral capsids composed of 252 capsomeres. The direct colorimetric diphenylamine assay indicated that MSDV has deoxyribonucleic acid as its nucleic acid. The above evidence demonstrates that MSDV is an avian adenovirus, the first recognized in the ring-necked pheasant (Phasianus colchicus L.).