title: A modified method for the assay of factor IX.
mesh_terms: D001921:Brain; D005164:Factor IX / Q000032:analysis*; D002836:Hemophilia B / Q000175:diagnosis; D006801:Humans; D066298:In Vitro Techniques; D008722:Methods; D013925:Thromboplastin; D014020:Tissue Extracts
chemical_list: D014020:Tissue Extracts; D005164:Factor IX; D013925:Thromboplastin