The important difference, he says, is "what you do with the blastocyst."

The odds of a blastocyst being healthy: 3 in 4.

However, the egg can split into two, but still have one blastocyst.

For this example, we use blastocysts from a grey mouse.

Only blastocysts found to be healthy are returned to the womb.

The resulting method yielded blastocysts 26 percent of the time.

As a result they decided to work with cultured blastocyst cells.

The donors of the blastocysts granted permission for them to be used in research.

This method is not suitable for late blastocysts - but see Section 3.6.2.

The blastocyst is growing and developing thanks to nourishment from your blood system.

It has usually reached the blastocyst stage at the time of implantation.

The healthiest one or two blastocysts are chosen for transfer.

The embryo is called a blastocyst at about the 6th day of development once it has reached nearly 100 cells.

At this stage of prenatal development, the embryo is a blastocyst.

Of the 16 blastocysts tested, 2 were absolutely perfect matches to Henry.

Human embryos reach the blastocyst stage 4-5 days after fertilization.

"It looked, to my eye, not like a cow blastocyst.

On average, only a small fraction of blastocysts yield stem cells.

The numbers of cells in blastocysts were analyzed using Student t-test.

Early development following the blastocyst stage is extremely rapid.

At that point the embryo is a hollow sphere called a blastocyst.

This new structure with a cavity in the center and the developing cells around it is known as a blastocyst.

The number of blastocysts that will be used if research goes ahead is likely to be strictly limited.

At the end of the culture period, the number of cells in blastocysts was examined.

This will lead to one inner cell mass and one blastocyst.