Immunoassay standardization
Scand.J.Clin.Lab Invest Suppl, (1991)Abstract
Assays employed in the biological sciences fall into two categories, which may be respectively termed "comparative" (or "functionally-specific") and änalytical" (or "structurally-specific"). The former are intended to compare the relative effects of substances, or mixtures of substances--not necessarily of identical chemical structure--on a biological system (e.g. whole animal, tissue, cell, etc). Results are represented by units of effect (i.e. they are not units of ämount" of the substance(s) measured), and differ depending on the biological system used. Such assays cannot be "standardised" by the use of a calibrant. In contrast, analytical assays are intended to measure the number of molecules (or mass) of a single substance of unique chemical structure in a test sample, and cannot legitimately be employed to measure mixtures of substances of different structure. Results are represented by units of molecular number or mass, and should be identical for any test sample irrespective