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Updated: Aug 10, 2026
Collection and Cryopreservation of Hamster Oocytes and Mouse Embryos
Published on: March 27, 2009
Normal fertilization and development of frozen-thawed mouse oocytes: protective action of certain macromolecules
J Carroll1, M J Wood, D G Whittingham
1MRC Experimental Embryology and Teratology Unit, St. George's Hospital Medical School, London, United Kingdom.
Abstract:
Freezing and thawing of mouse oocytes causes changes in the zona pellucida that reduce fertilization. The fertilization and development of oocytes were studied after freezing and thawing in media containing 1.5 M dimethylsulfoxide (DMSO) and various macromolecular supplements: BSA (Fraction V and crystalline), fetal calf serum (FCS), and polyvinyl alcohol (PVA). In conditions under which the fertilization rate of oocytes frozen in medium containing BSA was reduced, oocytes frozen in medium containing FCS were fertilized at rates approaching those of nonfrozen controls. Significantly fewer oocytes were fertilized after freezing in the presence of PVA than oocytes frozen in medium containing BSA or FCS. Fertilization of oocytes frozen in the presence of PVA was significantly increased when serum was included in the medium during dilution of the cryoprotectant. The in vitro and in vivo development of embryos obtained from frozen-thawed oocytes was independent of the macromolecular supplement used in the freezing medium and was similar to that of nonfrozen control oocytes. The results show that given the appropriate conditions for freezing and thawing, cryopreserved mouse oocytes undergo fertilization and development at rates similar to those for nonfrozen controls.
Insights
Cryopreservation of mouse oocytes using dimethylsulfoxide (DMSO) with fetal calf serum (FCS) supports fertilization and development. Optimal cryoprotectant dilution is key for successful oocyte cryopreservation and subsequent embryo development.
Area of Science:
- Reproductive Biology
- Cryobiology
- Developmental Biology
Background:
- Oocyte cryopreservation is crucial for assisted reproduction.
- Freezing and thawing can damage the zona pellucida, reducing fertilization rates.
- Macromolecular supplements are used to improve cryoprotective media efficacy.
Purpose of the Study:
- To evaluate the impact of different macromolecular supplements on mouse oocyte fertilization and development post-cryopreservation.
- To determine optimal conditions for cryopreservation media to maintain oocyte viability and function.
Main Methods:
- Mouse oocytes were frozen and thawed using 1.5 M dimethylsulfoxide (DMSO).
- Various macromolecular supplements including BSA, FCS, and PVA were tested in the freezing media.
- Fertilization rates and subsequent embryo development (in vitro and in vivo) were assessed.
Main Results:
- Oocytes frozen with FCS showed fertilization rates comparable to non-frozen controls.
- Oocytes frozen with PVA had significantly lower fertilization rates, which improved with serum during cryoprotectant dilution.
- In vitro and in vivo embryo development was unaffected by the type of macromolecular supplement used.
Conclusions:
- Fetal calf serum (FCS) is a suitable supplement for mouse oocyte cryopreservation, supporting high fertilization rates.
- Cryopreservation of mouse oocytes can achieve high fertilization and development rates when appropriate cryoprotectant and supplement conditions are employed.
- Cryopreserved oocytes can yield viable embryos, demonstrating the effectiveness of optimized cryopreservation protocols.
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