title: Rapid assay of murine leukemia virus helper activity for Friend spleen focus-forming virus.
mesh_terms: D000818:Animals; D005019:Ethyl Ethers / Q000494:pharmacology; D005557:Formaldehyde / Q000494:pharmacology; D005622:Friend murine leukemia virus / Q000032:analysis / Q000472:pathogenicity*; D006378:Helper Viruses / Q000032:analysis; D007106:Immune Sera / Q000494:pharmacology; D009052:Leukemia Virus, Murine / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity* / Q000528:radiation effects; D007942:Leukemia, Experimental / Q000382:microbiology / Q000473:pathology; D008297:Male; D008433:Mathematics; D008722:Methods; D051379:Mice; D011830:Radiation Effects; D013154:Spleen / Q000382:microbiology / Q000473:pathology*; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D005019:Ethyl Ethers; D007106:Immune Sera; D005557:Formaldehyde