Study on the nuclear polyhedrosis virus of Alphaea phasma Leech(ApNPV)-purification and characterization of ApNPY DNA

In this paper,report the purification and some characterization of ApNPV(virus particles and DNA.) After alkali-treatment polyhedra with 0.05M Na₂CO₃-0.05M NaCl,PH 10.8,(electron micrograph revealed) it was observed under electron microscope that the size of the virions/averages 55×333nm,and the size of the polyhedra averages 1.66μ.ApNPV DNA was isolated from ApNPV(virus particles multiply in the polyhedral matrix) after treated with TritonX-100,NaCl,DNase,RNase and pronase deproteinized by SDS-phenol method.Some of their physical properties were determined.The ApNPV DNA is a circular double stranded DNA molecule.Electron microscopic observation to this DNA preparation makes clear that the mean outer girth is about 16.8-32μ. The restriction endonuclease,EcoR Ⅰ,Bgl Ⅰ cleaved the ApNPV DNA 11,13 fragments respectively.By using molecule weight standard determining methods,the determining result is that the mol.wt.of ApNPV DNA is about 60×10⁶ dalton.