Viral Plaque AssaySkin Diseases, ViralCat DiseasesVirus ReplicationHemolytic Plaque TechniqueCell LinePlaque, AtheroscleroticDental PlaqueVirus CultivationTitrimetryAntibody-Producing CellsCytopathogenic Effect, ViralCalorimetryRickettsia rickettsiiRickettsia prowazekiiRickettsiaHaplorhiniPancreatinCulture TechniquesMethodsIdoxuridineNeutral RedVirologyVero CellsMethylcellulosePokeweed MitogensRickettsia typhiCercopithecus aethiopsNeutralization Tests