Direct radioimmunoassay of progesterone in mare plasma.

This research proposes a quick and cost-effective radioimmunologic method to measure progesterone levels in mare plasma directly. The procedure does not require plasma extraction and the results are consistent with radioimmunologic methods involving extracted plasma.

Overview of the Procedure

• The research revolves around direct radioimmunassay, a type of immunoassay where a radioactively labelled substance is used as a tracer to measure substances in a biological sample. This method was used for progesterone assay in mare plasma.
• The assay utilizes dextran-charcoal to absorb free progesterone. Dextran-charcoal is often used in radioimmunology to separate bound from unbound hormones.
• Notably, this method is conducted directly on 10 microliters of unextracted plasma, simplifying the procedure and reducing its cost.

The Assay Procedure

• The aqueous phase is decanted following adsorption of free progesterone on dextran-charcoal. Decanting in this context refers to the removal of a fermented or aged liquid from the solids that have settled at the bottom.
• The decanted phase is then extracted by 1 ml of scintillation fluid. Scintillation fluid is used to detect radioactive decay by scintillation counting.
• Then, the counting is performed directly on this two-phase system. A two-phase system involves a system with phases in two separate states of matter. Here, the two phases likely refer to the dextran-charcoal-progesterone complex and the plasma-scintillation fluid mixture.

Comparison of the Results

• Results obtained from this direct method are found to be comparable to those obtained with radioimmunoassays using extracted plasma. This implies that the test’s accuracy and sensitivity might be as good as traditional methods which involve plasma extraction.
• The main advantages of this proposed method are its low cost and speed, both of which could vastly improve the efficiency and affordability of progesterone testing in mare plasma.