A two-tiered testing process is used:

1) A portion of the hair sample is screened using an Enzyme Linked Immunosorbent Assay (ELISA) – a reliable and proven methodology for routine drug testing.

2) Any samples that are presumptively positive in the screening process are then confirmed, utilizing another portion of the hair sample, with either gas chromatography/mass spectrometry (GC/MS) or gas chromatography/mass spectrometry/mass spectrometry (GC/MS/MS).