Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) Enzyme Immunoassay (EIA) (1) (-) 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) Test Category Acids (2) Analgesics (2) Anticholinergics (1) Antihistamines (1) Antihypertensives (1) Antimicrobials (1) (-) Depressants (1) Test Sub-Category Opiates/Opioids (1) Test Test Name 2276U Heroin Metabolites - Free (Unconjugated), Urine