This test is valid for samples taken between 35 and 120 days after breeding.
Purpose of Test:
To test for
pregnancy in horses based on the level of PMSG (eCG)
Description of Test and Procedures:
The test is a radioimmunoassay performed with in-house reagents. The
radioimmunoassay technique is based on the competitive binding of the
serum and a radiolabeled hormone preparation. They compete for
binding to an antibody specific for the hormone being tested. The
antibody-bound radiolabeled hormone is separated and the quantity is
determined by counting on a gamma spectrometer.
Sample Needed and Procedures for Submittal:
Submit at least 1 mL of serum on a cold pack.
Schedule For Running Test:
The assay is set up Thursday and results are reported Monday afternoon. STAT assays
may be set up Monday-Thursday and results are reported the following day.
Interpretation of Results:
Results are reported as YES, NO or INCONCLUSIVE (MAYBE) based on the
relative level of PMSG (eCG) present in the sample. A pregnant mare
may test negative if the sample was taken too early (PMSG has not risen
yet) or too late (PMSG has already declined). Results for the
unknown are read by comparing them to serum of a known pregnant mare at
two different dilutions. If a sample drawn between 35-40 days
post-breeding and result is reported NOT PREGNANT, it is advised to
re-check in 1-2 weeks as in very few mares, production of hCG may have
Please note: This is not a quantitative assay. Therefore there are no normal values.