Cortisol, also known as hydrocortisone, is the major glucocorticoid produced and secreted by the adrenal cortex. It is present in blood as free protein or bound to cortisol binding protein (CBG) and is involved in regulation of glucose metabolism, fat degradation, blood pressure levels and stress inhibition. Cortisol also diffuses into cells, where its level is highly regulated by 11β-hydroxysteroid dehydrogenase (type 1 or 2). Based on our patented HTRF® technology, the cortisol assay allows for rapid and accurate cortisol measurement even in complex samples such as liver microsomes, whole cells and animal serum. This assay can also be used to assess 11β-HSD1 activity (native, recombinant or microsomal).