A rapid radioimmunoassay for serum testosterone

Area of Science:

• Endocrinology
• Biochemistry
• Laboratory Science

Background:

• Radioimmunoassay (RIA) is a common method for hormone quantification.
• Existing RIA methods may require extensive time, limiting their use in classroom settings.
• Accurate testosterone measurement is crucial for understanding male reproductive health.

Purpose of the Study:

• To develop a simplified and time-efficient RIA technique for classroom laboratory settings.
• To enable students to perform rat serum testosterone assays within two 3-hour periods.
• To validate the assay's performance and determine mean testosterone levels in Sprague-Dawley rats.

Main Methods:

• Utilized a commercially available testosterone RIA kit.
• Employed Subtilisin Carlsberg enzyme for steroid extraction from plasma proteins.
• Incorporated heat inactivation, cold storage, and Dextran-charcoal separation for assay completion.
• Established a standard curve for quantification.

Main Results:

• The developed RIA technique has a quantification range of 0.05 ng/ml to 5.0 ng/ml.
• The mean serum testosterone level in fifteen adult male Sprague-Dawley rats was determined to be 262 ng/100 ml.
• The assay is suitable for classroom laboratory settings, yielding results within two 3-hour periods.

Conclusions:

• A practical and efficient RIA method for determining rat serum testosterone has been established.
• This technique is well-suited for educational purposes, allowing hands-on experience with hormone assays.
• The assay provides reliable testosterone measurements, contributing to student learning in endocrinology and laboratory techniques.