Abstract
The object of this study was to adopt a triple-stain technique for identifying human acrosome-reacted spermatozoa and its simplified technique to boar spermatozoa. Spermatozoa were incubated in the uteri isolated from hamsters and mice and stained by these techniques. Stained smears disclosed spermatozoa with the following four patterns: a) light brown postacrosomal regions with red acrosomes (live sperm with normal acrosomes); b) light brown postacrosomal regions with unstained acrosomal regions or damaged acrosomes (live sperm without normal acrosomes); c) dark brown postacrosomal regions with dark red acrosomes (dead sperm with normal acrosomes); d) dark brown postacrosomal regions with unstained or dark blue acrosomal regions or damaged acrosomes (dead sperm without normal acrosomes). There was a significant positive correlation between the percentage of live sperm without normal acrosomes (category b) and that of zona-free hamster eggs penetrated (triple-stain technqiue: r=0.836; P<0.01; n=7, simplified technique: r=0.603; P<0.01; n=19). These results indicate that the technique can be used toidentify boar acrosome-reacted spermatozoa. However, staining by the simplified technique produced misleading results, i.e., a higher than "real" percentage oflive spermatozoa without normal acrosomes. This suggests that the triple-stain technique is more suitable for boar spermatozoa than the simplified technique.
