title: Fractionation of immune ribonucleic acid capable of inducing immunologic memory.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D002499:Centrifugation, Density Gradient; D005407:Flagella / Q000276:immunology; D007114:Immunization; D007156:Immunologic Memory; D051379:Mice; D012313:RNA; D012475:Salmonella / Q000276:immunology; D013154:Spleen / Q000276:immunology
chemical_list: D012313:RNA