Special remarks:

Intended use and principle of the test

125 I – Radioimmunoassay for the quantitative determination of Metanephrine and Normetanephrine in urine.

First, Metanephrine (Metadrenaline) and Normetanephrine (Normetadrenaline) are quantitatively acylated.

The assay procedure follows the basic principle of radioimmunoassay, involving competition between a radioactive and a non-radioactive antigen for a fixed number of antibody binding sites. The amount of 125I-labelled antigen bound to the antibody is inversely proportional to the analyte concentration of the sample. When the system is in equilibrium, the antibody bound radioactivity is precipitated with a second antibody in the presence of polyethylene glycol. The precipitate is counted in a gamma counter.

Quantification of unknown samples is achieved by comparing their activity with a reference curve prepared with known standards.