title: Caffeine no longer measurable with theophylline channel of the TDx.
mesh_terms: D001322:Autoanalysis; D002110:Caffeine / Q000097:blood*; D003429:Cross Reactions; D006801:Humans; D013806:Theophylline / Q000097:blood*
chemical_list: D002110:Caffeine; D013806:Theophylline