Two strains of mouse embryos at the four- and eight-cell stages had biopsy specimens obtained by means of two different mechanical techniques: aspiration and displacement. Embryos and biopsy specimen cells were evaluated for survival and development. Blastomere acquisition rates were significantly higher with the displacement biopsy technique; however, no difference in survival or developmental rates was found in blastomere biopsy specimens removed from either four-cell or eight-cell embryos. A maximum of one blastomere can be removed from a four-cell embryo, whereas three blastomeres can be taken at biopsy from an eight-cell mouse embryo without significantly affecting embryo development, although mouse strain differences were noted. Intact, viable, biopsied blastomeres will develop in vitro when cocultured with morphologically intact embryos. Births of live offspring after embryo biopsy are reported.

This study investigated the development potential of equine embryos in vitro after biopsy and vitrification. Twenty embryos were obtained from Quarter Horse, Thoroughbred, and mix-breed light mares between three and ten years old. The twenty embryos were divided into a biopsy (n=10) and control group (n=10). The biopsy group underwent microaspiration biopsy using a micromanipulator to obtain a small tissue sample from the embryo. Both groups were then vitrified using a commercially available technique originally described by Carnevale (2006) at Colorado State \ University. All 20 embryos were cultured in DMEM/Hams F-12 medium under oil at 37°C in 5% CO2 in air (Hinrichs et al., 1990). Embryos were monitored for expansion and hatching. Embryo development was statistically different between the two groups (p<0.05). The biopsy procedure did result in a much lower development potential in the biopsy group as compared to the control group (20% vs. 80%). However, embryos in the biopsy group did show expansion and hatching therefore the combined procedure did not preclude development potential in vitro. Based on these findings, more research needs to be done to increase the success of the combined procedure and the ultimate viability of the embryos needs to be confirmed with the establishment of successful pregnancies.

Assisted reproductive technology procedures has become a more complex treatment over the years after implementation of preimplantation genetic diagnostics and cryopreservation methods such as slow freeze and vitrification. When embryos undergo these methods they are exposed to external damage that threaten to affect their quality and thereby lead to lower survival rates and lower pregnancy rates. The aim of this study was to document blastocysts quality after vitrification, re-vitrification and preimplantation genetic diagnosis with subsequent vitrification. A total of 126 blastocysts were collected, of which 119 blastocysts were documented with the help of an experienced embryologists and the remaining seven blastocysts were from a new series of re-vitrified embryos. The 126 collected blastocyst were allocated into groups depending on their degree of preimplantation genetic diagnosis and vitrification. The gathered data was scoring according to morphology, expansion and proportion of necrotic cells at 2 and 4 hours of the expansion phase. Fisher exact test was used for statistical evaluation. There were no significant difference when comparing data before and after vitrification and preimplantation diagnosis, which indicates that these methods do not cause morphological damage to the blastocyst.