Isolation of host-cell nuclei from chick intestinal cells infected with second-generation schizonts of Eimeria...

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 coccidial 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.