Cryopreservation is used for blastocyst preservation of most mammalian embryos and is an important technique for breeding. We aimed to compare the efficiency of the cryopreservation method using the standard Cryotop device and the ReproCarrier device, a domestic product manufactured in Korea. The efficacy of the two devices was analyzed based on the survival rate, intracellular levels of reactive oxygen species (ROS), and apoptosis of the vitrified bovine blastocysts. The survival rates of the vitrified-warmed blastocysts were similar between the ReproCarrier group (58.4 ± 17.7%) and Cryotop group (59.9 ± 14.1%). Intracellular ROS levels and apoptotic index were determined by DCFDA staining and TUNEL assay. Changes in intracellular ROS levels, number of total nuclei, and cellular apoptosis of vitrified blastocysts after cryopreservation were not significantly different between the two groups. These results indicate that the ReproCarrier device method is as effective as the standard Cryotop method for vitrification of bovine blastocysts in vitro.

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSION
CONFLICTS OF INTEREST
ACKNOWLEDGEMENTS
AUTHOR CONTRIBUTIONS
AUTHOR’S POSITION AND ORCID NO
REFERENCES

• Jin-Woo Kim(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea, Institute of Infertility, Daegu University, Gyeongsan 38453, Korea)
• Seul-Gi Yang(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea, Institute of Infertility, Daegu University, Gyeongsan 38453, Korea)
• Hyo-Jin Park(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea, Institute of Infertility, Daegu University, Gyeongsan 38453, Korea)
• Ju Hwan Kim(Modu Science, Sejong 30128, Korea)
• Dong-Mok Lee(Modu Science, Sejong 30128, Korea)
• Seong-Min Woo(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea)
• Hyun-Jeong Kim(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea)
• Hyun Ah Kim1(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea)
• Jae-Hoon Jeong(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea)
• Min Ji Lee(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea)
• Deog-Bon Koo(Department of Biotechnology, College of Engineering, Daegu University, Gyeongsan 38453, Korea, Institute of Infertility, Daegu University, Gyeongsan 38453, Korea) Corresponding author