4.3
PROCESS
OF
EXTRACTION
OF
STEM
CELLS
FROM
HUMAN
EMBRYONIC STEM CELLS
In vitro fertilization generates multiple embryo. The surplus embryos is not clinically used or is suitable for implantation into cell and therefore may be donated by the the donor with consent. Human embryonic stem cells are derived from these donated embryos that would be otherwise discarded. These procedures below are the steps to extract the human embryonic stem from the human embryo. 1. The inner cell mass (cells of interest) from the blastocyst stage of the embryo, is separated from the trophectoderm, the cells that would differentiate into extraembryonic tissue. 2. Immunosurgery, the process in which antibodies are bound to the trophectoderm and removed by another solution and mechanical dissection are performed to achive separation. 3. The resulting inner cell mass cells are plated onto cells that will supply support. 4. The inner cell mass cells attach and expand further to form a human embryonic cell line which are undifferentiated. 5. These cells are fed daily and are enzymatically or mechanically separated every four to seven days. 6. For differentiation to occur, the human embryonic stem cell line is removed from the supporting cells to form embryoid bodies, is co-cultured with a serum containing necessary signals or is grafted in a three dimensional scaffold to result.
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