title: Letter: Tissue thromboplastin and activated partial thromboplastin reagents.
mesh_terms: D001780:Blood Coagulation Tests; D006801:Humans; D007202:Indicators and Reagents; D013925:Thromboplastin / Q000032:analysis*
chemical_list: D007202:Indicators and Reagents; D013925:Thromboplastin