title: The preservation of standard sera for helminth complement fixation tests.
mesh_terms: D001793:Blood Preservation; D003168:Complement Fixation Tests; D005612:Freeze Drying; D005615:Freezing; D006373:Helminthiasis / Q000276:immunology*; D006801:Humans; D007106:Immune Sera; D009584:Nitrogen; D012552:Schistosomiasis / Q000276:immunology; D013997:Time Factors
chemical_list: D007106:Immune Sera; D009584:Nitrogen