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) (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) Therapeutics (10) Test Category Depressants (1) Test Sub-Category Opiates/Opioids (1) Test Test Name 2276B Heroin Metabolites - Free (Unconjugated), Blood