Corticosterone, a glucocorticoid synthesized in the adrenal cortex upon ACTH stimulation, serves as both the biosynthetic precursor of aldosterone and a key biomarker of stress. Stress-induced elevations in corticosterone have been linked to impaired long-term memory retrieval, chronic increases following dietary restriction, and marked rises after burn injury. Beyond its role in the stress response, corticosterone also helps shape sleep–wake cycles.

The RayBio^® Corticosterone Enzyme Immunoassay (EIA) Kit (EIA-CORT2) is a competitive immunoassay that quantifies corticosterone in serum or plasma from human, porcine, feline, canine, rabbit, equine, and sheep samples (not rat or mouse) within 2.5 hours. Absorbance is measured at 450 nm and values are interpolated from a ready-to-use corticosterone standard curve. The assay demonstrates a sensitivity of 0.0021 ng/ml and has been validated for linearity, stability, precision, and spike-recovery performance. Each kit provides sufficient reagents to perform up to 96 assays, including standard curve and unknown samples.

• Various species
• High sensitivity
• Rapid detection within 2.5 hours
• Good characteristics in terms of linearity, stability, precision, and spiking & recovery

• Pre-Coated 96-well Strip Microplate
• Assay Diluent
• Lyophilized Standard
• Positive Control
• Capture Antibody
• HRP-conjugated secondary antibody
• Wash Buffer
• TMB One-Step Substrate Reagent
• Stop Solution

• Microplate reader capable of measuring absorbance at 450 nm
• Precision pipettes to deliver 2 μL to 1 mL volumes
• Adjustable 1-25 mL pipettes for reagent preparation
• 100 mL and 1-liter graduated cylinders
• Distilled or deionized water
• Tubes to prepare standard or sample dilutions
• Orbital shaker
• Software which can perform four-parameter logistic regression models

1. Prepare all reagents, samples and standards as instructed.
2. Add 50 µL standards or samples to appropriate well. Incubate for 10 minutes at room temperature.
3. Add 50 µL Capture Antibody to appropriate well. Incubate 1 hour at room temperature or 37°C. And wash 5 times.
4. Add 100 µL prepared HRP-Secondary antibody solution. Incubate 1 hour at room temperature or 37ºC. And wash 5 times.
5. Add 100 µL TMB One-Step Substrate Reagent to each well. Incubate 5-20 minutes at room temperature or 37°C.
6. Add 50 µL Stop Solution to each well. Read at 450 nm immediately.

The entire kit may be stored at -20°C to -80°C for up to 6 months from the date of shipment. For extended storage, it is recommended to store it at -80°C. Avoid repeated freeze-thaw cycles.