Direct solid-phase enzymoimmunoassay of testosterone in saliva

Area of Science:

• Endocrinology
• Biochemistry
• Assay Development

Background:

• Accurate measurement of salivary testosterone is crucial for various medical applications.
• Existing methods often require complex extraction and chromatographic steps, limiting throughput.
• A simplified, high-throughput assay for salivary testosterone is needed.

Purpose of the Study:

• To develop and validate a competitive, solid-phase enzyme immunoassay for testosterone in saliva.
• To assess the assay's performance, including detection limit, correlation with extraction methods, and precision.
• To evaluate the assay's suitability for large-scale sample analysis in clinical and research settings.

Main Methods:

• A competitive, solid-phase enzyme immunoassay was performed on microtiter plates.
• The assay utilized an overnight incubation period.
• No chromatographic or extraction steps were employed prior to analysis.

Main Results:

• The assay demonstrated a detection limit of 230 fg per well (16.1 pmol/L) with overnight incubation.
• A high correlation (r=0.95) was observed between testosterone concentrations measured with and without prior saliva extraction.
• Within- and between-assay coefficients of variation ranged from 5.5-13.2% for control samples.

Conclusions:

• The developed enzyme immunoassay provides a simple, accurate, and efficient method for salivary testosterone determination.
• The assay's ability to bypass extraction steps and its high throughput make it suitable for reproductive and sports medicine.
• This method is particularly advantageous for projects involving serial sampling and large numbers of samples.