Stem cells hold much promise in bringing about medical breakthroughs in form of treatment for previously incurable diseases and conditions like cancer, Alzheimer’s disease, Parkinson’s disease or paralysis. These “blank” cells are capable of self-rejuvenation and also transforming into a functional cell; it is these attributes of a stem cell that make them invaluable to scientists. However, to experiment on the stem cells, they must at first be obtained and the mode of collection is where the controversy originates. There are two main types of stem cells, embryonic and adult stem cells. In order to collect the pluripotent embryonic stem cells, the human embryo must be killed as it can only be extracted from the innermost cellular layers of the blastocyst after just four days of fertilization. It is therefore not hard to understand as why killing a human embryo, which could have otherwise been borne as a human baby, is considered equivalent to murder by a lot of people. Even people who would not go as far as calling it murder, usually admit to the procedure being disturbing in terms of ethics at least.
Adult stem cells come from various sources and contrary to what the name may suggest, it does not only come from fully grown human beings. It is just that they are comparatively grown and different than the embryonic stem cells. The placenta and the umbilical cord blood are both rich sources of adult stem cells, the former being even richer than the latter. Our bone marrow contains multipotent stem cells and it is possible to extract these cells clinically, but the procedure is immensely painful for the donor and may even be considered risky. Unlike the extraction of the embryonic stem cells, extracting adult stem cells is not controversial. Ethicists do not support the killing of an embryo for the sake of medical progress, however bright the future may seem, but bio ethicists do understand the importance of stem cell experimentation and thus do not consider extraction of adult stem cells from various sources to be unethical as long as it is agreed upon voluntarily by the donor or the guardian of the concerned source.