Sperm may be tested for the presence of essential molecules, such as Oocyte Activating Factor, and for normal expression of surface and internal proteins. We provide some of these tests on an experimental basis, and collaborate in a sperm proteomics project in which we hope to identify proteins that are missing or modified in infertile men. Please call for details.
In past decades, several sperm function tests were very popular. Today they are rarely used. One was the Zona-free Hamster Oocyte Sperm Penetration Assay (SPA or HOP Test). It tested the ability of sperm to acrosome react, fuse with a (hamster) egg, and start to form a pronucleus. This was very useful in that it measured several key events needed for fertilization. However, it was very laborious and expensive. Some versions of this test were more predictive of fertilization success than others, but all lost favor when ICSI became available.
Another highly successful test was the “Hemi-Zona Assay”, or human zona binding test. Here, human zonae pellucidae were collected from dead human eggs, and used to test the ability of sperm to bind to them. This is another essential step leading to fertilization. Today, few human zonae are available, and ICSI has diminished the demand for the test. We can still do this in special circumstances.
Above, hamster zona-free oocyte with a decondensed human sperm in the cytoplasm. Right, two intact human zonae with human sperm bound to their surfaces.
