An enzyme-linked immunosorbent assay for stanniocalcin, a major hypocalcemic hormone in teleost

An enzyme-linked immunosorbent assay (ELISA) was developed to quantify stanniocalcin (STC) levels in tissue extracts and plasma samples. The detection limit of the competitive ELISA described is 0.2 ng STC per well, allowing detection of 3.7 pmol.liter −1 (assuming a molecular mass of 54,000 Da for native STC). The particular antiserum detects STC in plasma obtained from a variety of freshwater and seawater species. In freshwater post-smolt Salmo salar plasma, STC levels were significantly lower (around 0.74 nmol.liter −1) than those of seawater smolts (around 2.78 nmol.liter −1). Seven days after removal of Stannius corpuscles from freshwater eels a significant hypercalcemia was observed as well as a drop in plasma STC levels (from 2.33 to 0.67 nmol.liter −1).