Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (1) Sample Type 24 Hour Urine (1) (-) Blood (1) Serum or Plasma (1) Urine (2) Test Area Therapeutics (1) Test Category Acids (1) Antidepressants (1) Antiepileptics/Antiseizures (3) Antihistamines (1) Antineoplastics (1) Antipsychotics (3) Antirheumatics (1) Biomarkers (1) (-) Bronchodilators (1) Cholinesterase Inhibitors (1) Diuretics (1) Immunosuppressants (3) Muscle Relaxants (1) Other (1) Solvents (2) Terpenes (1) Vasodilators (1) Volatiles (2) Test Sub-Category (-) Other (1) Toxic Elements (5) Test Test Name 4387B Theophylline, Blood