Stem Cell Lines
A stem cell line is a group of stem cells all originating from a single original cell. They replicate in vitro - outside of the body - for an indefinite length of time. Due to a special, constant environment, as they replicate, the stem cells keep their plasticity, meaning that they remain undifferentiated, so that they can later become specialized cells. Theoretically, if proper conditions are met, a stem cell line could continue to grow for as long as conditions continue to stay the same. Each cell will be identical to all others in the stem cell line provided that no mutation occurs.
Cells grown in stem cell lines are intended to be used in research. Because the line keeps replicating, scientists don't need to harvest more stem cells from new embryos or other sources if they use cells from established stem cell lines.
In 2001, President Bush mandated that scientists using federal funds could only use the human stem cell lines established by that date for research. This means that any researcher wanting to use stem cells from a newer line now has to find private funding.
In the long term, this will place severe restrictions on the research that scientists can accomplish with these cells. The limited number of stem cell lines available limits the genetic diversity of available for research. Also, because the lines are older, they do not grow as well as newer lines. Because the DNA in stem cell lines can change over time due to natural mutations, it is also possible for genetic flaws to be passed on in the existing stem cell lines, limiting their usefulness for research.
Therefore, there is a rift in people's opinions of whether or not new stem cell lines should be available for publicly funded research in the U.S. This would mean more possibilities for medical research, but it would also mean more human fertilized eggs discarded from infertility clinics could be used to create more stem cell lines.
How Cord Blood Can Help
Cord blood can help in with this problem because it also contains stem cells. The use stem cells taken from cord blood to create new embryonic stem cell lines poses no harm to and potential human life, and the stem cells taken from cord blood are just as useful as those taken from embryos. This could increase the number of stem cell lines available for research without utilizing embryos or harming the mother or child donating the cord blood in any way.