were washed in PBS, then fixed for 15 min in 4% paraformaldehyde in PBS, and embryos were permeabilized with 0.
It was performed nucleus staining of total cell in blastocysts
for assessing the blastocyst
were incubated for 15 min at 39[degrees] C in the basic medium (H-SOF containing 5 mg/ml BSA) supplemented by 10 mg/ml propidium iodide (PI).
Consider next the NAS prohibition on building certain kinds of part-human chimeras, those resulting from the transfer of human embryonic stem cells into nonhuman primate blastocysts
and those involving the transfer of any embryonic stem cells into human blastocysts
These days, a five-cocktail probe can test blastocysts
for autosomal trisomies such as Down syndrome; autosomal monosomies; X and Y numerical disorders such as Turner's syndrome and Klinefelter's syndrome; and translocations using fluorescent in situ hybridization (FISH).
The researchers successfully collected embryonic stem cells from 20 of the cloned blastocysts
, and by tweaking the timing of the nuclear transfer and other technical considerations, were able to produce a single embryonic cell line.
Instead, the South Korean scientists harvested cells from the interior of their cloned blastocysts
and discarded the remainder.
The quality of blastocysts
was assessed by differential staining of the inner cell mass (ICM) and trophectoderm (TE) cells according to the modified staining procedure described by Thouas et al.
Scientists could not find out how long the cubs took to grow inside their mothers because they had no way of knowing when the blastocysts
In this process, fertilized eggs are grown in the laboratory for a few extra days so that doctors can more clearly determine which cell configurations, known as blastocysts
, will be healthy.
Thomson grew his embryonic stem cells from the inner cell mass of blastocysts
left over from a fertility treatment and due to be discarded.
When enough genetically identical blastocysts
have been cultured, they are implanted inside a surrogate uterus and allowed to grow to term.
Since all comprehensive chromosomal screening techniques take longer than a single day, blastocysts
are cryopreserved using a new vitrification technique, which has resulted in 100 percent blastocyst
In humans as well as in pigs, in vitro culture conditions are suboptimal and result in low blastocyst
rates or blastocysts
with low cell numbers and a lack of a distinct inner cell mass (ICM) (Pickering et al.
PGD is used to prevent specific diseases, often in couples who are not infertile but carry a risk of passing on genetic disorders, while PGS is generally used in infertile patients or those with recurrent pregnancy loss to identify the most normal appearing blastocysts
for transfer back into the uterus.