Embryonic stem cells are stem cells taken from an early embryo.
Source
They are usually obtained from the inner cell mass of a blastocyst, about 5 days after fertilisation. The embryos used are generally spare embryos created during in vitro fertilisation (IVF) treatment that would otherwise be discarded. Removing the inner cell mass destroys the embryo. The cells are grown in culture, where they can divide many times to produce a large supply.Potency
Cells from the inner cell mass are pluripotent: they can differentiate into any type of body cell. Cells taken from an even earlier embryo, up to about the 8-cell stage, are totipotent.Advantages
• They can form any type of body cell, so they could treat a wide range of conditions, such as spinal cord injuries, heart damage or type 1 diabetes.
• They divide rapidly in culture.
• They can be used to study early development and to test drugs.Disadvantages
• Cells from another person's embryo may be rejected by the patient's immune system.
• It is difficult to control their differentiation, and if they keep dividing they may form tumours.Ethical issues
The main objection is that obtaining the cells destroys an embryo. Some people believe that life begins at fertilisation, so an embryo has the same right to life as a person. Others argue that an early embryo has no nervous system and cannot feel pain, and that spare IVF embryos would be destroyed anyway.In the UK, research on embryos is regulated by the Human Fertilisation and Embryology Authority (HFEA). Embryos can only be used with the donors' consent and must not be kept beyond 14 days after fertilisation.
SourceThey are usually obtained from the inner cell mass of a blastocyst, about 5 days after fertilisation. The embryos used are generally spare embryos created during in vitro fertilisation (IVF) treatment that would otherwise be discarded. Removing the inner cell mass destroys the embryo. The cells are grown in culture, where they can divide many times to produce a large supply.Potency
Cells from the inner cell mass are pluripotent: they can differentiate into any type of body cell. Cells taken from an even earlier embryo, up to about the 8-cell stage, are totipotent.Advantages
• They can form any type of body cell, so they could treat a wide range of conditions, such as spinal cord injuries, heart damage or type 1 diabetes.
• They divide rapidly in culture.
• They can be used to study early development and to test drugs.Disadvantages
• Cells from another person's embryo may be rejected by the patient's immune system.
• It is difficult to control their differentiation, and if they keep dividing they may form tumours.Ethical issues
The main objection is that obtaining the cells destroys an embryo. Some people believe that life begins at fertilisation, so an embryo has the same right to life as a person. Others argue that an early embryo has no nervous system and cannot feel pain, and that spare IVF embryos would be destroyed anyway.In the UK, research on embryos is regulated by the Human Fertilisation and Embryology Authority (HFEA). Embryos can only be used with the donors' consent and must not be kept beyond 14 days after fertilisation.