Corticosterone is a glucocorticoid secreted by the cortex of the adrenal gland in response to the stimulation by adrenocorticotropic hormone. Corticosterone is a major indicator of stress in non-human mammals. Glucocorticoids, such as corticosterone, guide fundamental processes associated with converting sugar, fat, and protein stores to useable energy; inhibiting swelling and inflammation; and suppressing immune responses following a stress event.

Measuring Corticosterone

Competitive immunoassays, RIA and EIA methods, are the typical means for measuring levels of corticosterone in biological matrices. Most RIAs or EIAs require solvent extraction techniques to measure serum or plasma corticosterone levels, however extraction may be very difficult or impossible with mouse samples due to the large volumes of plasma or serum required for most extraction protocols.

Our Corticosterone EIA (K014-H1 and K014-H5) and CLIA (K014-C1 and K014-C5) kits overcome this serum and plasma volume problem by allowing the steroid to be measured using 1-2 ?L of mouse serum or plasma. Serum or plasma samples are treated with an equal volume of a special Dissociation Reagent that liberates the corticosterone from any binding proteins. The mixture is then diluted 1:50 fold or greater with assay buffer and added directly to the well of the provided microtiter plate.

The EIA provides results in 90 minutes and the chemiluminescent immunoassay (CLIA) assay takes 2 hours. The EIA now spans 10,000 to 78 pg/mL and the CLIA has a range from 3,000 to 12.3 pg/mL with a measured sensitivity of 6.7 pg/mL. The CLIA allows concentrations of <0.004 μM of corticosterone to be measured. Typical c57bl/6j mouse serum corticosterone levels fall at 0.08 ± 0.01 ?M and therefore can be measured in this assay without extraction.

Comparison of our EIA and CLIA Corticosteone Assays

Customers Validation Data

Comparison of our EIA with a Commercial RIA

Comparison using 1 ?L Mouse Serum