Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) Enzyme-Linked Immunosorbent Assay (ELISA) (1) (-) Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GC/MS) (1) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (13) Sample Type Blood (2) Serum or Plasma (1) (-) Urine (1) Test Area Therapeutics (1) Test Category (-) Analgesics (1) Antianxiety (1) Antidepressants (4) Drugs of Abuse (8) Drugs of Abuse, Therapeutics (4) Hallucinogens (1) Therapeutics (3) Test Sub-Category Opiates/Opioids (1) Test Test Name 8721U Meperidine and Metabolite, Urine