2007-01-04 23:54:45 · 4 answers · asked by Dana S 1 in Science & Mathematics ➔ Biology
Most stem cell researchers use embryos that were created but not used in in vitro fertility treatments to derive new stem cell lines. Most of these embryos are slated to be destroyed, or stored indefinitely. In the United States alone, there have been estimates of at least 400,000 such embryos. The embryonic blastocyst is dissected at a very early stage and the the enbryoblast cells removed and cultured on liquid or solid media.
Stem cells can also be derived from adult progenitor cells and adult stem cells, but it is still not clear whether adult stem cells can be "pluripotent", meaning able to differentiate into any type of cell. In this case the stem cells are removed from the bone marrow or like tissue, and cultured like embryonic stem cells.
2007-01-05 01:02:19 · answer #1 · answered by floundering penguins 5 · 0⤊ 0⤋
This depends what type of stem cells you are referring to. Embryonic stem cells, the controversial ones, are harvested from the blastocyst of an in vitro fertilized embryo. These cells have the ability to differentiate into any cell in the human body. But all normal humans have stem cells within them. Mostly located in the bone marrow, these cells have the capability to become a good number of cell types, but are more limited than embryonic stem cells.
2007-01-05 01:58:17 · answer #2 · answered by NML 1635 3 · 0⤊ 0⤋
Adult stem cells for bone marrow transplants are obtained by apheresis. The donor is given a drug, G-CSF, which releases the stem cells from their bone marrow and then collected by apheresis.
2007-01-05 04:20:16 · answer #3 · answered by <3 Chrissy 4 · 0⤊ 0⤋
stem cells can be obtained from embroynic tissue as this tissue has the ability to divide and from bone marrow of adult tissue as this is also very capable to divide and give large number of blood cells
2007-01-05 00:15:17 · answer #4 · answered by Anonymous · 0⤊ 0⤋