Vitrification of mouse oocyte using open pulled straws compared with needles

To compare the survival rate of mouse oocytes and fertilization rate between using open pulled straws (OPS) and needles for vitrification. Meiosis II oocytes from female C57B/6J mice aged 7-8 weeks were collected and allocated to two groups for vitrification by using OPS or needles. Vitrified oocytes were thawed, morphological survival and fertilization rate were examined. There was no obvious difference between the morphological survival rates of vitrified mouse oocytes using OPS and needles (66.7% vs 64.8%). Proportions Difference 1.9% (95% CI -7.1, 10.7). The vitrified oocytes from the needle had significantly higher percentages of fertilization rate than OPS (76.8% vs 62.5%). Proportions Difference -14.3% (95% CI -24.5, -3.6). Vitrification method of mouse oocytes using needles when compared to OPS provides a similar morphological survival rate and higher fertilization rate.