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Updated: Aug 9, 2026
Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids
Published on: April 25, 2016
[The determination of cortisol in plasma with a direct luminescence enzyme immunoassay]
F Hofmann1, W Hubl, D Meissner
1Institut für Klinische Chemie und Laboratoriumsdiagnostik, Bezirkskrankenhauses Dresden-Friedrichstadt.
Insights
This study introduces a new luminescent immunoassay for measuring cortisol. The assay is sensitive, precise, and avoids sample extraction, showing good agreement with ELISA.
Area of Science:
- Biochemistry
- Immunology
- Analytical Chemistry
Context:
- Accurate cortisol measurement is crucial for diagnosing adrenal disorders.
- Conventional methods like ELISA can be time-consuming and require sample extraction.
- Development of rapid, sensitive, and extraction-free immunoassays is needed.
Purpose:
- To develop and validate a novel luminescent immunoassay for quantifying cortisol in plasma.
- To assess the assay's sensitivity, precision, and agreement with established techniques.
- To eliminate the need for sample extraction in cortisol determination.
Summary:
- A luminescent immunoassay utilizing horseradish peroxidase and a chemiluminescent reaction was developed.
- Cortisol is released from plasma proteins by heating or adding 8-aniline-1-naphthalene sulfonic acid.
- The assay demonstrated high sensitivity and precision across a broad cortisol concentration range.
- Results showed excellent correlation with conventional enzyme-linked immunosorbent assay (ELISA) methods.
- No prior extraction of cortisol from plasma samples was required.
Impact:
- Provides a sensitive, precise, and efficient alternative for plasma cortisol analysis.
- Simplifies the diagnostic workflow by eliminating the need for sample extraction.
- Facilitates improved clinical management of endocrine diseases related to cortisol levels.
Abstract:
The assay is based on the luminescent measurement of horseradish peroxidase. The IgG fraction of a cortisol antiserum is coated on suitable polystyrene tubes (in use for the measurement of luminescence). The enzyme activity of bound label was determined using a p-iodophenol enhanced chemiluminescent reaction. The assay was sensitive and precise for a wide cortisol concentration range and showed a good agreement with conventional ELISA-technique. There was no extraction necessary for cortisol from plasma. The diluted sample was heated to 60 degrees C or 8-aniline-1-naphthalene sulfonic acid was added in order to release cortisol from protein binding in plasma.
