title: Virus particles and antigens in natural orf.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D003168:Complement Fixation Tests; D004474:Ecthyma, Contagious / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology*; D008854:Microscopy, Electron; D011212:Poxviridae / Q000276:immunology*; D012698:Serologic Tests; D012756:Sheep; D012867:Skin / Q000382:microbiology
chemical_list: D000956:Antigens, Viral