title: Effect of heterologous combination on competitive nephelometric immunoassay. I. Site-heterologous combination for theophylline immunoassay.
mesh_terms: D005779:Immunodiffusion; D009391:Nephelometry and Turbidimetry; D011863:Radioimmunoassay; D013806:Theophylline / Q000032:analysis*
chemical_list: D013806:Theophylline