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) Enzyme Immunoassay (EIA) (1) (-) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (3) Sample Type Blood (1) Serum or Plasma (1) Urine (1) Test Area (-) Drugs of Abuse (3) Therapeutics (13) Test Category Depressants (3) Test Sub-Category Carboxylic Acids (2) (-) Opiates/Opioids (3) Test Test Name 2276B Heroin Metabolites - Free (Unconjugated), Blood 2276SP Heroin Metabolites - Free (Unconjugated), Serum/Plasma 2276U Heroin Metabolites - Free (Unconjugated), Urine