Numerous studies reported that vitrification, an ultra-rapid cooling technique, seems to be highly effective and could increase oocyte survival rate rather than slow freezing. The successful of oocyte vitrification depends on the proper combination of type and concentration of cryoprotectant. This study was addressed to determine the effects of the combination of type and concentration of cryoprotectants of vitrification media, notably in the embryo development. This experimental research was conducted by using oocyte obtained from thirty-two adult female Deutschland, Denken and Yoken (DDY) mice (7-8 weeks old). The MII mice oocytes were vitrified within 24 h after retrieval using the Cryotop method with cryoprotectants as follow : sucrose (16.5% EG, 16.5% DMSO, 0.5 mol/l sucrose), trehalose (16.5% EG, 16.5% DMSO, 0.5 mol/l trehalose) and Kitazato. The embryo development and morphological grading was observed at 2-cell and 8-cells under reverse phase light microscope and inverted microscope. This study demonstrated a good embryo development and morphological grading in sucrose and trehalose vitrification media. In embryo development, trehalose medium seems more superior compared to sucrose medium, even though Kitazato was the most superior compared to both. In the morphological grading, in 2-cells embryo, there were no significant differences between the three cryoprotectants, While, in 8-cells embryo, trehalose medium appeared to be superior compared to sucrose medium, even though seemed more inferior compared to Kitazato. The appropriate type and concentration of sugar as extracellular cryoprotectant was trehalose in oocyte vitrification based on embryo development, compared to sucrose.

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As well as the development of assisted reproductive technology (ART), as the current treatment of woman who failed in achieving pregnancy, the development of an advance vitrification method also grows rapidly. The successful of oocyte vitrification depends on the type and the concentration of cryoprotectant. This study was addressed to elaborate empirical evidence and recent studies of sucrose and trehalose as an extracellular CPA with the aim of achieving the success of oocyte vitrification. Several researchers in agreement that trehalose, as extracellular cryoprotectant, also has a role as intracellular cryoprotectant by microinjection with high survival rates as the outcome. Moreover, the combination of sucrose or trehalose as an extracellular cryoprotectant and others intracellular cryoprotectant have different survival rates which might occur because of the differences between the composition and concentration of sucrose or trehalose. The appropriate type and concentration of sugar as an extracellular cryoprotectant for oocyte cryopreservation are sucrose or trehalose in 0.5M concentration. Nevertheless, it requires further study to optimize oocyte vitrification process.