Product Overview: Why Measure Cortisol?
Cortisol is a steroid hormone produced by the adrenal cortex in response to stress and low blood glucose. It plays essential roles in glucose metabolism, immune regulation, anti‑inflammatory responses, and maintenance of blood pressure. Dysregulation of cortisol levels is associated with Cushing’s syndrome, Addison’s disease, chronic stress, depression, and metabolic disorders. Accurate quantification of Human Cortisol is critical for:
- Stress and neuroendocrine research
- Circadian rhythm studies
- Diagnosis and monitoring of adrenal disorders
- Metabolic and cardiovascular disease investigations
- Psychoneuroimmunology and behavioural research
Yanda Bio’s Human Cortisol ELISA Kit uses a validated sandwich immunoassay format (not competitive) to deliver precise, reproducible results. As a professional manufacturer with > 6,000 detectable targets and long‑standing collaborations with over 60 Chinese universities, we combine deep endocrinology expertise with rigorous quality control to support your research.
Superior Quality Metrics
- Intra‑assay CV < 5 % — excellent within‑run precision
- Inter‑assay CV < 8 % — outstanding run‑to‑run consistency
- High specificity — no cross‑reactivity with other human corticosteroids or related molecules
Kit Components: What’s Inside
| Component | 96‑Well Configuration | 48‑Well Configuration |
|---|---|---|
| Microplate (Pre‑coated) | 8 wells × 12 strips | 8 wells × 6 strips |
| Standards | 0.3 mL × 6 tubes | 0.3 mL × 6 tubes |
| Sample Diluent | 6 mL | 3 mL |
| HRP‑Conjugated Detection Antibody | 6 mL | 3 mL |
| 20× Wash Buffer | 25 mL | 15 mL |
| Substrate A | 6 mL | 3 mL |
| Substrate B | 6 mL | 3 mL |
| Stop Solution | 6 mL | 3 mL |
| Plate Sealer | 2 sheets | 2 sheets |
| Manual | 1 copy | 1 copy |
Note: This kit uses a sandwich ELISA format with HRP‑labelled detection antibody.
Assay Principle: Sandwich ELISA
This kit employs a solid‑phase sandwich enzyme‑linked immunosorbent assay. The microplate is pre‑coated with a monoclonal antibody specific for Human Cortisol. Standards and samples are added, allowing cortisol to bind to the immobilised antibody. After washing, a Horseradish Peroxidase (HRP)‑conjugated detection antibody is added, forming an antibody‑antigen‑antibody “sandwich”. Following a second wash, TMB substrate is added. The HRP enzyme catalyses a blue colour that turns yellow upon acidification. The optical density (OD) at 450 nm is directly proportional to the cortisol concentration in the sample.
Sample Dilution Note: Samples are pre‑diluted 5‑fold during the procedure; multiply results by 5 to obtain actual concentrations.
Sample Collection & Preparation
| Sample Type | Collection & Processing |
|---|---|
| Serum | Use pyrogen/endotoxin‑free tubes. Avoid cell stimulation. Centrifuge at 3000 rpm for 10 minutes. |
| Plasma | Use EDTA, citrate or heparin anticoagulant. Centrifuge at 3000 rpm for 30 minutes. |
| Cell Supernatant | Centrifuge at 3000 rpm for 10 minutes to remove particles. |
| Tissue Homogenate | Homogenise tissue in PBS (1:9 w/v), centrifuge at 5000×g for 10 minutes at 2–8 °C. Collect supernatant. |
| Storage | Aliquot and store at –20 °C (≤ 1 month) or –80 °C (≤ 2 months). Avoid repeated freeze‑thaw cycles. |
Materials Required But Not Provided
- Microplate reader (450 nm)
- Precision pipettes and tips (0.5–10 μL, 2–20 μL, 20–200 μL, 200–1000 μL)
- 37 °C incubator or water bath
Important Notes for Assay Procedure
- Store the kit at 2–8 °C. Bring all reagents to room temperature for 20 minutes before use. Concentrated wash buffer may crystallise; dissolve crystals in a warm water bath.
- Return unused strips to the resealable bag with desiccant and store at 2–8 °C. Use promptly.
- The S0 standard (zero concentration) is the negative control/blank. Multiply final results by 5 (dilution factor).
- Strictly adhere to incubation times, volumes and sequence.
- Mix all liquid components thoroughly before use.
Reagent Preparation
20× Wash Buffer Dilution: Dilute 1 part 20× wash buffer with 19 parts distilled water to obtain 1× working wash buffer.
Washing Method
Manual: Aspirate liquid, fill each well with wash buffer, stand for 1 min, aspirate, and tap dry on absorbent paper. Repeat 5 times.
Automatic washer: Inject 350 μL per well, soak for 1 min, wash 5 times.
Assay Procedure
- Remove required strips after 20 min equilibration. Reseal unused strips and return to 4 °C.
- Standard wells: add 50 μL of each standard concentration.
- Sample wells: add 10 μL sample + 40 μL sample diluent. Blank wells: leave empty.
- Add 100 μL HRP‑conjugated detection antibody to all wells except blanks. Seal and incubate at 37 °C for 60 min.
- Aspirate, wash 5 times (manual or automatic).
- Add 50 μL Substrate A and 50 μL Substrate B to each well. Incubate at 37 °C in the dark for 15 min.
- Add 50 μL stop solution. Measure OD at 450 nm within 15 min.
Data Analysis
Plot standard curve: OD values (y‑axis) vs. standard concentrations (x‑axis) in Excel or curve‑fitting software (linear regression, R ≥ 0.9900). Calculate sample concentrations from the curve, then multiply by the dilution factor (5×).
Kit Performance Specifications
| Parameter | Performance |
|---|---|
| Accuracy | Standard curve linear regression coefficient (R) ≥ 0.9900 |
| Sensitivity | Minimum detectable concentration < 10.0 pg/mL |
| Detection Range | 50 – 1600 pg/mL |
| Specificity | No cross‑reactivity with other human corticosteroids (corticosterone, aldosterone, etc.) |
| Intra‑assay CV | < 5 % |
| Inter‑assay CV | < 8 % |
| Storage | 2–8 °C, protect from light and moisture |
| Shelf Life | 6 months |
Related Products (Recommended for Comparative Studies)
Expand your endocrine research with these complementary assays:
- Rat Cortisol ELISA Kit — for translational studies using rat models of stress and adrenal function
- Human Corticosteroid‑Binding Globulin (CBG) ELISA Kit — measures the primary carrier protein for cortisol, allowing free vs. total cortisol calculations
Using these kits together provides a complete picture of the hypothalamic‑pituitary‑adrenal (HPA) axis.
Special Offer
Buy any three ELISA kits from Yanda Bio and enjoy free shipping. Combine Human Cortisol, Rat Cortisol, and Human CBG kits to build a comprehensive stress‑endocrine panel at exceptional value.
Comparison with Premium International Brands
Yanda Bio’s human ELISA kits deliver performance equivalent to leading international brands at 40–60 % lower cost. Our direct‑to‑researcher model and efficient manufacturing eliminate unnecessary markups. With superior precision (CV < 5 % intra‑assay, < 8 % inter‑assay) and 3–7 day custom development, we offer an unbeatable combination of quality, speed and affordability.
Disclaimer
Strict adherence to the protocol is required. Yanda Bio is not responsible for results obtained from deviations. This product is for research use only; not for clinical diagnosis or human use. The user assumes all responsibility for any consequences arising from misuse.
Ordering & Contact Information
To order this Human Cortisol ELISA Kit (Cortisol ELISA Kit for sale), or to inquire about volume discounts, custom development, and format selection, please contact our sales team.
