Embryonic Stem Cells for Research Applications essays

Embryonic Stem Cells for Research Applications essays Embryonic stem cells are undifferentiated cells that can divide indefinitely and develop into more mature, specialized cells. In the course of development, they ultimately become skin cells, neurons, muscle, blood cells and every other of the 220 cell types that make up the tissues and organs in the body. Through years of research, scientists have found that stem cells show an ability to divide indefinitely in their undifferentiated state in the laboratory. Although stems cells also exist in adult humans, embryonic stem cells are the most researched and debated. Currently, the U.S. has had limited federal funding of embryonic stem cells to the 60 stem cell lines that already exist. This is very unfortunate since it limit's the potential benefits that new stem cell lines might offer. The embryos from which human embryonic stem cells are derived are typically from four or five-day-old blastocysts. The blastocyst includes three structures: the trophoblast, which is the layer of cells that surrounds the blastocyst; the blastocoel, which is the hollow cavity inside the blastocyst; and the inner cell mass, which is a group of approximately 30 cells at one end of the blastocoel. Human embryonic stem cells are isolated by transferring the inner cell mass into a petri dish containing a culture medium. The inner surface of the culture dish is typically coated with a feeder layer, consisting of mouse embryonic skin cells that have been treated so they will not divide. The feeder cells release nutrients into the culture medium and act as a sticky surface allowing the inner cell to attach. Recently, scientists have begun to devise ways of growing embryonic stem cells without the mouse feeder cells. This is a significant scientific advancement because of the risk that virus es or other macromolecules in the mouse cells may be transmitted to the human cells. For several days, the cells of the inner cell mass proliferate, and when this occurs, the...