[Treatment of sperm samples for the diagnostic examination of the ultrastructure of bull spermatozoa].

Methods proposed by various authors for the treatment of spermatozoa for ultrastructural study were tested under the conditions of our laboratory. The methods were studied as to their applicability to the diagnostic examination of fresh and frozen sperm under electron microscope. A suitable method was developed and proposed for diagnostic purposes; the method consists of double fixation, 1.25% glutaraldehyde in phosphate buffer, or the formaldehyde fixative PAF (Stefanini et al., 1967), being used for the first fixation, and 1% osmium tetroxide (OsO4) after Caulfied (1957) being used for postfixation. The suspension of spermatozoa is filtered through the Sympor milipore filters and the sediment is embedded in the Durcupan ACM embedding medium. Ultrathin slices are contrasted by means of uranyl-acetate and lead citrate. This method also enables a quantitative evaluation of samples and is suitable for fresh and deep-frozen bull semen.