BACKGROUND The standard embryo cryopreservation method is still less than optimal for biopsied embryos. The aim of this study was to compare the survival of biopsied embryos cryopreserved with four different methods using non-transferable embryos. METHODS Abnormal embryos from one or three pronuclei and spare embryos of grade 3 and 4 were used for this study. Non-biopsied embryos were cryopre...

BACKGROUND Recent advancement of minimum volume vitrification methods has resulted in a dramatic increase in the efficiency of the process. The aim of this study was to estimate the cumulative reproductive outcome of a cohort of infertile couples undergoing ICSI and oocyte vitrification in restrictive legal conditions, where only a limited number of oocytes could be inseminated per cycle and em...

Oocyte vitrification has been introduced into clinical settings without extensive pre-clinical safety testing. In this study, we analysed major safety aspects of human oocyte vitrification in a high security closed system: (i) chromosomal meiotic segregation, (ii) embryonic developmental kinetics and (iii) DNA (hydroxy)methylation status. Fresh and vitrified sibling oocytes from young donors af...

Cryopreservation of matured oocytes is a useful technique because the oocytes can be used for some assisted reproductive technologies after warming. Even though rats, like mice, have been used in various research fields including reproductive technology, information about cryopreservation of rat oocytes is limited. The objective of the present study was to improve the vitrification protocol for...

The cryoloop is a technique where a thin nylon loop is used to suspend a film of cryoprotectant containing the oocytes and directly immersing them in liquid nitrogen. 508 bovine oocytes were collected, of these 351 were cryopreserved by slow freezing using standard straws or a new vitrification method using our self-constructed cryoloops and the remainder were controls. After thawing, the oocyt...

BACKGROUND The objective of this study was to investigate the effect of vitrification and in vitro maturation on the mitochondrial distribution and ATP content of oocytes. METHODS The oocytes at Germinal Vesicle (GV) and Metaphase II (MII) stages were recovered from 6-8 week old NMRI strain female mice. The oocytes were divided into vitrified and non-vitrified groups. Vitrification was done b...

Ovarian tissue cryopreservation is the key step towards the establishment of an ovarian tissue bank or the preservation of ovarian tissue for patients scheduled for gonadotoxic cancer therapies, aiming for fertility restoration later on. Conventional cryopreservation, or slow freezing, has been the mainstay of ovarian tissue cryopreservation. Vitrification has recently emerged as a new trend fo...

Oocyte vitrification causes a temporary disassembly of the metaphase plate and spindle, which needs time to recover after warming. As a consequence, early post-fertilization events-such as timing of second polar body extrusion-might be altered, with unknown effects on preimplantation development, timing to pronuclear breakdown, and timing of cleavages. The aim of this study was to evaluate if d...

The aim of this study was to determine the optimum conditions for vitrifying in vitro produced day 7 porcine embryos using different vitrification devices and blastocoele collapse methods. Firstly embryos were collapsed by micro-pipetting, needle puncture and sucrose with and without conducting vitrification. In the next experiment, non-collapsed embryos were vitrified in an open device using e...