Akademik Veri Yönetim Sistemi
CELL PRESERVATION TECHNOLOGY, cilt.4, sa.3, ss.199-208, 2006 (SCI-Expanded)
It is well known that an effective freezing technique is crucial for small numbers of human sperm using empty zona pellucida as straws. However, this method still has problems. The goal of this study was to find an optimal cryoprotective medium and freezing protocol for testicular sperm using slow freezing-rapid thawing with a programmable freezer. In this study, the main solutions were human serum albumin supported Earle's balanced salt solution, human serum albumin added to follicular fluid, blastocyst culture medium, follicular fluid alone, 8% glycerol and finally aspirated oocyte cytoplasm, which is called Osmangazi-Turk solution. A slow-programmed cryomachine and 1,2-propanadiol were used as if freezing oocytes or embryos. The piezzoelectric method was applied in order to overcome the difficulty of injection into the totally empty zona pellucida. In the present study it has been observed that the new Osmangazi-Turk solution provides better protection for both sperm nuclear chromatin and midpiece and sperm motility that is necessary in fertilization and healthy embryo development. In the evaluation of the effects of cold shock in freeze/thaw procedures, sperm motility is not the only parameter; the intactness of sperm nuclear chromatin and mid-piece should also be taken into consideration. Small numbers of sperm injected into empty zona pellucida should not be frozen by conventional sperm freezing protocols but rather by routine oocyte or embryo freezing protocols. This method allows us to have well-protected sperm with the use of species-specific (human) ooplasm instead of egg yolk.