Detection and elimination of cellular nucleic acids in biologicals produced on continuous cell lines

Experiments have been conducted to determine the extent to which currently available purification techniques can remove contaminating substrate cellular DNA from inactivated poliovirus vaccine produced on continuous cell lines rising highly [32P]-labeled, nick-translated cellular DNA added to poliovirus suspensions, we found that purification procedures were capable, in small-scale experiments, of reducing contaminating DNA by factors of 10(3) (DNAse treatment followed by gel filtration) and 10(3)-3X10(5) (ion exchange chromatography). Sequential application of these purification steps should reduce contaminating cellular DNA to acceptable levels. We also examined the potential usefulness of immobilized nucleic acid hybridization techniques for the routine direct testing of residual cellular nucleic acids in final production lots of inactivated poliovirus vaccine and other biologicals. A filter hybridization test, using [32P]-labeled, nick-translated cellular DNA as a probe, was capable of detecting 40 pg of homologous cellular DNA. Using probes of higher specific activity the assay should be sensitive enough for use in routine quality control.