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) Enzyme Immunoassay (EIA) (2) (-) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (1) Sample Type Blood (1) Serum or Plasma (1) (-) Urine (1) Test Area (-) Drugs of Abuse (1) Exposure (3) Therapeutics (6) Test Category Depressants (1) Test Sub-Category Opiates/Opioids (1) Test Test Name 2276U Heroin Metabolites - Free (Unconjugated), Urine