Capillary electrophoresis-based immunoassay for cortisol in serum

Area of Science:

• Analytical Chemistry
• Biochemistry
• Clinical Diagnostics

Background:

• Cortisol measurement is crucial for diagnosing adrenal disorders.
• Existing immunoassays may require extensive sample preparation.
• Capillary electrophoresis (CE) offers high-resolution separation for complex biological samples.

Purpose of the Study:

• To develop a novel competitive immunoassay for cortisol.
• To utilize capillary electrophoresis (CE) coupled with laser-induced fluorescence.
• To enable direct analysis of cortisol in unprocessed serum samples.

Main Methods:

• Synthesis and purification of fluorescein-labeled cortisol.
• Production and purification of anticortisol Fab fragments.
• Development of CE separation conditions for serum analysis.
• Quantification of cortisol using serum calibration curves.

Main Results:

• High reproducibility in separating free and bound labeled cortisol.
• No requirement for prior serum sample cleanup.
• Successful establishment of serum calibration curves for cortisol quantitation.
• Demonstrated feasibility of the CE-based immunoassay for direct serum analysis.

Conclusions:

• A novel competitive immunoassay for cortisol using CE and laser-induced fluorescence is feasible.
• The assay allows direct analysis of serum samples without prior cleanup.
• This method shows potential for routine clinical diagnostics of cortisol levels.