objective: vitrification has been shown as one of the most effective methods of cryopreservation for mammalian embryos. however, there is no consensus which stage of embryonic development is the most appropriate for vitrification with subsequent maximal development after thawing. this study was carried out to explore and compare the effect(s) of vitrification on mouse 2-cell, 4-cell, 8-cell, mo...

BACKGROUND Current outcome results with embryos derived from thawed MII human oocyes are significantly lower than with embryos cryopreserved at the pronuclear stage. Here, we investigated whether freezing-thawing was associated with changes in oocyte mitochondrial polarity (DeltaPsim) that could influence competence by altering ATP levels or the ability of the cytoplasm to regulate intracellula...

nowadays gamete and embryo freezing is an appropriate approach for preserving of genetic traits in laboratory animals, rare and endangered species. frozen cells are suitable replace for actively breeding animals colony. the aim of this study was to perserve laboratory mouse embryo, using vitrification method and comparing effect of two cryoprotectants, glycerol-sucrose(gs) and ethylene glycol-f...

Continuous improvements to assisted reproductive technology (ART) have facilitated the advancement and preservation of animal genetics as well as animal reproductive efficiency. One of the ART techniques is cryopreservation which facilitates embryo transfer procedures. In the present experiment embryos produced in vivo or in vitro were transferred to the recipient ewes just after collection (fr...

BACKGROUND Cryopreservation of supernumerary embryos is routinely performed in human-assisted reproduction, providing a source of embryos which can be thawed for use in subsequent treatment cycles. However, the viability of cryopreserved embryos has traditionally relied on morphological assessment, which is a poor predictor of embryo health since freezing leads to a significant overall reductio...

The relationship between the presence of cystic and/or haemorrhagic follicles in both donor and recipient does and survival at birth of frozen-thawed embryos (778 embryos transferred) from 3 selected rabbit strains (NZ: New Zealand white; SY and SB: synthetic breeds) were studied. Donor does (SY:108; NZ:99; SB:96) were mated and treated with 25 IU of hCG. Only morphologically normal oviductal m...

BACKGROUND Abnormalities of oocyte morphology affect embryo quality and viability. Whether morphological abnormalities of the oocyte influence cryosurvival and further development of derived embryos is not known. The aim of this study was to compare cryosurvival and progression to the blastocyst stage of frozen-thawed embryos derived from normal and abnormal oocytes. METHODS A total of 5292 G...

In-vitro fertilization patients (n = 15) at risk of ovarian hyperstimulation syndrome (OHSS) (oestradiol > or =4500 pg/ml on the day of human chorionic gonadotrophin administration and 25 or more follicles of intermediate or large size) underwent aspiration of all follicles and cryopreservation of all fertilized oocytes at the pronuclear stage. Patients were monitored for up to 2 weeks post-ret...

Development of an efficient cryopreservation technique for the domestic ferret is key for the long-term maintenance of valuable genetic specimens of this species and for the conservation of related endangered species. Unfortunately, current cryopreservation procedures, such as slow-rate freezing and vitrification with open pulled straws, are inefficient. In this report, we describe a pipette ti...

OBJECTIVE To compare cryopreservation of mature human oocytes with slow-rate freezing and vitrification and determine which is most efficient at establishing a pregnancy. DESIGN Prospective randomized. SETTING Academically affiliated, private fertility center. PATIENT(S) Consenting patients with concerns about embryo cryopreservation and more than nine mature oocytes at retrieval were ran...