Corticosterone is a glucocorticoid produced by the adrenal cortex in response to ACTH (corticotropic hormone) and is the precursor to aldosterone. The production of glucorcorticoids is increased by stress; therefore, corticosterone can be used as a biomarker of stress.1 Biologists often measure corticosterone in fecal material of the species they are studying.1,2 This non-invasive sample collection procedure has the advantage of not itself causing stress and thereby increasing corticosterone levels, a common problem when samples for measurement of corticosterone are collected by more invasive means.1 Plasma corticosterone levels have a circadian variation and corticosterone may be important in the regulation of the sleep-wake cycle.2,3 Cayman’s Corticosterone ELISA Kit is a competitive assay that can be used for quantification of corticosterone in serum and rodent feces.Needed but not supplied: Please download the kit booklet to verify if UltraPure Water (Milli-Q or equivalent) or any other components are needed for this assay.WARNING This product is not for human or veterinary use.