title: The NP activation test for assay of avian leukosis-sarcoma viruses.
mesh_terms: D001355:Alpharetrovirus / Q000302:isolation & purification*; D000818:Animals; D000906:Antibodies; D002471:Cell Transformation, Neoplastic; D002999:Clone Cells / Q000254:growth & development; D003168:Complement Fixation Tests; D003470:Culture Media; D046508:Culture Techniques; D004372:Ducks; D004625:Embryo, Nonmammalian; D005347:Fibroblasts; D006378:Helper Viruses; D008722:Methods; D014762:Viral Interference; D014776:Virus Cultivation
chemical_list: D000906:Antibodies; D003470:Culture Media