title: Use of the U.S. Opacity Standard.
mesh_terms: D022121:Cholera Vaccines / Q000592:standards; D005898:Glass / Q000592:standards*; D008027:Light; D009391:Nephelometry and Turbidimetry; D010567:Pertussis Vaccine / Q000592:standards; D012485:Salmonella typhi; D014436:Typhoid-Paratyphoid Vaccines / Q000592:standards; D014481:United States
chemical_list: D022121:Cholera Vaccines; D010567:Pertussis Vaccine; D014436:Typhoid-Paratyphoid Vaccines