Published online by Cambridge University Press: 06 April 2009
A procedure is described for the preparation of purified nuclei of chick intestinal cells infected with Eimeria necatrix. During second-generation schizogony the host-cell membrane becomes resistant to homogenization, hypotonic shock and ultrasonication. However, brief treatment with a low concentration of trypsin (0·001 ) will disrupt the cell membrane. Thereafter, the nuclei can be selectively harvested from contaminating nuclear types and schizonts by a series of centrifugations. Electron microscopy and Feulgen—DNA microspectrophotometry showed that the nuclear preparations retained their integrity with little, if any, loss of DNA. Chemical determinations confirmed that host-cell nuclear DNA synthesis was stimulated by conccidial infection and further established that quantitatively there was a coincident increase in the amount of host nuclear RNA during schizogony. It is now feasible to examine directly the effects of coccidial infection upon the host's nuclear apparatus.