Zona pellucida binding assay--a method for evaluation of canine spermatozoa

The present study describes the use of a zona pellucida binding assay for the evaluation of canine spermatozoa. A zona pellucida binding assay is a sperm evaluation test that is practical to perform and provides potentially useful information on the damage caused to spermatozoa by new methods of sperm storage. The addition of the detergent Equex STM paste to the cryopreservation extender has a positive effect on the zona pellucida binding capacity of cryopreserved spermatozoa. A large number of sperm-oocyte complexes need to be evaluated because of the variability in sperm binding capacity among oocytes. However, this does not constitute a major problem as canine oocytes can be stored before use in a zona pellucida binding assay and sperm-oocyte complexes can be fixed and stored until evaluation.