A direct dot-enzyme immunoassay to detect human ovulation.

Area of Science:

• Reproductive endocrinology
• Immunodiagnostics
• Biochemical assays

Background:

• Accurate ovulation prediction is crucial for fertility management and assisted reproductive technologies.
• Existing methods for monitoring ovulation can be complex, invasive, or lack sensitivity for early detection.
• Urinary estrogen levels, particularly the pre-ovulatory surge, are key indicators of impending ovulation.

Purpose of the Study:

• To develop and validate an original dot-enzyme-linked immunosorbent assay (ELISA) for predicting ovulation.
• To detect the pre-ovulatory estrogen peak in early morning urine samples.
• To assess the feasibility of adapting this assay for a reliable home-use kit.

Main Methods:

• A dot-ELISA was developed using a monoclonal anti-estrogen antibody capable of detecting free estrogens and their urinary metabolites.
• Antigen was immobilized on a nitrocellulose membrane, and urine was incubated with the antibody.
• Peroxidase-labeled secondary antibodies were used for detection, with coloration inversely proportional to estrogen levels.

Main Results:

• The dot-ELISA successfully detected the pre-ovulatory estrogen surge, showing no coloration during the surge and maximal coloration at basal levels.
• Results were compared across six menstrual cycles against radioimmunoassay (RIA) measurements of urinary estrogens and basal body temperature (BBT) data.
• The assay demonstrated validity in identifying the pre-ovulatory signal, correlating with established ovulation markers.

Conclusions:

• The developed dot-ELISA is a valid method for predicting ovulation through the detection of urinary estrogen peaks.
• The assay's ability to work with early morning urines and its sensitivity suggest potential for home-use applications.
• Further adaptation is required to establish this methodology as a reliable home kit for ovulation prediction.