14) After 5-6 days hES cells are "harvested" from the inner cell mass
of the blastocyst.
Embryonic stem cells are found in the inner cell mass
of the human blastocyst that exists from the fourth to the seventh day after fertilization.
Human embryonic stem cells (HESCs) are usually isolated manually from the inner cell mass
of an embryo grown in vitro by a skilled technician using a micromanipulator-controlled micropipette and microscope.
They would then take out the stem cells from its inner cell mass
and dope them with the appropriate hormones and proteins to turn the stem cells into, say, heart tissue, which could then be used to repair your ailing heart.
In the latter case, the line between cellular life and organismic death is less clear-cut; in removing the inner cell mass
from a blastocyst, the Thomson method is seen as killing an embryo that is still alive, albeit certain to die because discarded.
It does this by secreting protein-digesting enzymes that digest the outermost portion of the uterine wall, enabling it to bury itself there, with the side containing the inner cell mass
, the "blastoderm," coming into contact first.
The Court appears to have clearly focused its decision on those processes relying on now dated traditional and destructive methods for generating embryonic stem cells from the inner cell mass
of embryos, yet seems to provide for a continuing basis for patentability of process of generating human embryonic stem cells and products derived from those cells where non-destructive techniques can be used.
The total cell number, as well as differential cell numbers representing the inner cell mass
(ICM) and trophectoderm were determined by a differential staining technique for blastocysts.
This low success rate is assumed to be a cumulative result of losses at different stages of pregnancy due to several unknown causes including chromosomal abnormalities, low cell number and altered inner cell mass
(ICM) rate of blastocysts, irregular-sized blastomeres, and cytoplasmic fragmentation (Wang et al.
Embryonic stem cells are derived from the inner cell mass
of blastocysts, which are hollow balls of cells that form in early development.
Worcester, MA) announced the decision of the Board of Patent Appeals and Interference, interference number 105,192, between itself and Geron Corporation over methods of producing cultured inner cell mass
(CICM) cells, often referred to as embryonic stem cells.
Hwang's team made history when they removed the inner cell mass
(cells that become the embryo) from the blastocyst and grew the cells in a nutrient-rich petri dish.