Definition - What does Assay mean?
An assay, in medical testing, is a test done to detect the presence, amount, or potency of a substance found in a sample. In other words, a test to determine something about a substance. In terms of drug testing, a type of assay known as an immunoassay is performed to detect the presence of drug metabolites in urine.
WorkplaceTesting explains Assay
An assay, in medical and drug testing, involves the introduction of a specific, fixed amount of an outside element into a sample in order to observe the reaction between the outside element and the substances found in the sample. These reactions allow for both the detection of the substance and (in some cases) the measurement of the amount of that substance present. An immunoassay is a type of assay used in urine drug testing which can detect the presence of drug metabolites utilizing the introduction of an antigen or an antibody.