Testing Terminology

Laboratory Analysis Methods:

Enzyme immuno asssay (EIA) – an assay that uses an enzyme-bound antibody to detect antigen. The enzyme catalyzes a color reaction when exposed to substrate.

Enzyme-linked immunosorbent assay (ELISA) – a sensitive immunoassay that uses an enzyme linked to an antibody or antigen as a marker for the detection of a specific protein, especially an antigen or antibody. It is often used as a diagnostic test to determine exposure to a particular infectious agent, such as the AIDS virus, by identifying antibodies present in a blood sample.

Gas chromatography (GC) – a technique for analysing a mixture of volatile substances in which the mixture is carried by an inert gas through a column packed with a selective adsorbent and a detector records on a moving strip the conductivity of the gas leaving the tube. Peaks on the resulting graph indicate the presence of a particular component. Also called gas-liquid chromatography.

Mass spectrometry (MS) – an analytical chemistry procedure in which ions, produced from a sample, are separated by electric or magnetic fields according to their ratios of charge to mass. A record is produced (mass spectrum) of the types of ion present and their relative amounts.

Liquid chromatography (LC) –  an analytical chromatographic technique that is used to separate ions or molecules that are dissolved in a solvent.

Gas chromatography–mass spectrometry (GC-MS) – a method that combines the features of gas chromatography and mass spectrometry to identify different substances within a test sample.

Tandem mass spectrometry (MS/MS) – a procedure that involves multiple steps of mass spectrometry selection, with some form of fragmentation occurring in between the stages.