PP-13 THE EFFECT OF DIFFERENT COOLING AND WARMING RATES ON HUMAN BLASTOCYST VITRIFICATION RESULTS

Abstract

Method: We used two different protocols for vitrification of cord blood cells. Dimethylsulphoxide was used as a cryoprotectant in both methods. BSA and dextran 40 were used in different amounts in different vitrification solutions. Before and after the vitrification process, cell viabilities were assessed by trypan blue dye method. The differences in CD34+ cell ratios were defined by flow cytometry and differences in morphology by the light microscope. Results: We isolated 57.09±9.50×1,000,000 mononuclear cells. We obtained 93.8%±4.40 viable cells from the cord blood samples. CD34+ cell ratio was 0.47±0.2%. The viable cell ratio was 60.61±11% after the first vitrification technique and 66.63±9.9% after the second technique. In the light microscopical analysis, the swelling and aggregation of the cells were evident. CD45+, CD34+ and CD34+/45+ cell ratios were significantly decreased after both vitrification techniques. However, there were no significant differences between two different methods in terms of CD34+, CD45+ and CD34+/45+ cell viabilities. The viable cells in the second technique was more than the first technique. Conclusion: We concluded that the cord blood CD34+ cells were more sensitive to vitrification than the mononuclear cells. All antigens may have not been detected in the present study due to the possible damages on the cell surface. The techniques we used are rapid, cheap and easier than the slow-freeze techniques. We suggest that these rapid vitrification methods must be improved with further studies.