Introduction
Corticotropin-releasing factor (CRF) (also known as Corticotropin-releasing hormone (CRH) is a 41-amino acid peptide hormone secreted by the paraventricular nucleus (PVN) of the hypothalamus in response to stress. Its main function is the stimulation of the pituitary synthesis of adrenocorticotropic hormone (ACTH), as part of the hypothalamic–pituitary–adrenal axis (HPA axis). CRF levels may be associated with Alzheimer's disease and major depression. CRF is also synthesized in peripheral tissues, such as T lymphocytes, and is highly expressed in the placenta, suggesting roles in parturition.
The RayBiotech CRF Enzyme Immunoassay (EIA) Kit is an in vitro quantitative assay for detecting CRF peptide based on the competitive enzyme immunoassay principle. In this assay, a biotinylated CRF peptide is spiked into the samples and standards. The samples and standards are then added to the plate, where the biotinylated CRF peptide competes with endogenous (unlabeled) CRF for binding to the anti-CRF antibody. After a wash step, any bound biotinylated CRF then interacts with horseradish peroxidase (HRP)-streptavidin, which catalyzes a color development reaction. The intensity of the colorimetric signal is directly proportional to the amount of captured biotinylated CRF peptide and inversely proportional to the amount of endogenous CRF in the standard or samples. A standard curve of known concentration of CRF peptide can be established and the concentration of CRF peptide in the samples can be calculated accordingly.
Product Features
- Strip plates and additional reagents allow for use in multiple experiments
- Quantitative protein detection
- Establishes normal range
- The best products for confirmation of antibody array data
Application Notes
Kit Components
- Pre-Coated 96-well Strip Microplate
- Wash Buffer
- Standard Peptide
- Assay Diluent(s)
- Biotinylated Peptide
- HRP-Streptavidin
- TMB One-Step Substrate
- Stop Solution
- Assay Diagram
- Positive Control Sample
- Capture Antibody
- User Manual
Other Materials Required
- Distilled or deionized water
- 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
- Tubes to prepare standard and sample dilutions
- Orbital shaker
- Aluminum foil
- Saran Wrap
- Absorbent paper
- Microplate reader capable of measuring absorbance at 450nm
- SigmaPlot software (or other software that can perform four-parameter logistic regression models)
Protocol Outline
- Prepare all reagents, samples and standards as instructed.
- Add 100 µl detection antibody to each well.
- Incubate 1.5 h at RT or O/N at 4°C.
- Add 100 µl standard or sample to each well.
- Incubate 2.5 h at RT.
- Add 100 µl prepared streptavidin solution.
- Incubate 45 min at RT.
- Add 100 µl TMB One-Step Substrate Reagent to each well.
- Incubate 30 min at RT.
- Add 50 µl Stop Solution to each well.
- Read plate at 450 nm immediately.
Storage/Stability
Standard, Biotinylated CRF / CRH peptide, and Positive Control should be stored at -20°C after arrival. Avoid multiple freeze-thaws. The remaining kit components may be stored at 4°C. Opened Microplate Wells and antibody (Item N) may be stored for up to 1 month at 2° to 8°C. Return unused wells to the pouch containing desiccant pack and reseal along entire edge.