Research or Therapeutic Cloning

  1. Research or Therapeutic Cloning
  2. Science & Policy History
  3. Ethics
  4. Media Monitoring
  6. References & Links

The technical name for cloning is somatic cell nuclear transfer (SCNT).  Once an embryo is created by SCNT it can be inserted into the womb of a recipient (reproductive cloning) or it can be used for research purposes (particularly with the aim of creating stem cells).  This second process has often been described as “therapeutic cloning”.  However some have argued that this terminology is highly misleading as to-date no form of therapy has resulted from SCNT.  Hence the phrase “research cloning” may represent a more neutral and honest form of terminology.  However at present this terminology has not gained widespread acceptance. 

Science & Policy History

Basic scientific concepts 

Diagrams courtesy of the Association of Reproductive Health Professions. Cloning and Genetic Modification is a publication of the Association of Reproductive Health Professionals ( Here is a link to the complete diagram/brochure as posted on the ARHP site.


A gene is a hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome.  Chromosomes consist of long coiled chains of genes and are found within all nucleated cells in the human body.  Human beings normally have 23 pairs of chromosomes; one of each pair is inherited from the genetic mother and one from the genetic father. 

In sexual reproduction, a child receives half of their genes from the mother (contained in the egg) and half from the father (contained in the sperm).  The combination of maternal and paternal genes which occurs at fertilisation forms the basis of human genetic variety and diversity.  A small amount of genetic material is contained within mitochondria within the egg and this mitochondrial DNA is passed on to the child entirely from the mother. The procedure of somatic cell nuclear transfer (SCNT), is as follows1:

  • The nucleus is removed from an egg leaving the cytoplasm and mitochondria (cellular components derived from the mother)
  • A body (or somatic) cell is taken from an adult individual who is to be cloned.  The DNA is extracted from the nucleus and inserted into the prepared egg.
  • The new cell is then induced to divide using either chemical or electrical stimulation, thereby commencing the development of an embryo.




 In reproductive cloning the embryo is then placed into a womb and allowed to develop into a child.  In research cloning the embryo is used for research purposes, for example to generate embryonic stem cells2, leading ultimately to its destruction.  

Of course embryos created through the normal process of in vitro fertilisation can also be used for research purposes, including the generation of embryonic stem cells.  Research cloning has the potential to lead to the creation of embryonic stem cells which would be genetically identical to the donor of the original body cell.  Hence this procedure would in theory allow the generation of genetically identical replacement tissues for individual patients.  Tissues created in this way would carry little or no chance of immunological rejection.  Research cloning may also be used to create stem cells from individuals who suffer from specific genetic conditions or variants.  This may enable research into the fundamental developmental biology of genetically inherited disease.   


Key Events in the Development of Research Cloning & Stem Cell Research3 

1928Hans Spemann conducts the first nuclear transfer experiment.
1950sScientists begin work on cloning frogs. See BioCentre guide on reproductive cloning for further info.
1981Mouse embryonic stem cells isolated.
1988First umbilical cord blood transplant.
1988A group of researchers in the US report that it is possible to produce a stable cell line in the laboratory derived from human embryos.
1990Human Fertilisation and Embryology Act passed, primarily to regulate the practice of in vitro fertilisation.
1996Dolly the sheep is born, the first mammal “cloned” through cell nuclear replacement technique.
1998Human Fertilisation and Embryology Authority and Human Genetic Advisory Committee report published, suggesting recommendations to extend regulations for 1990 Act.
1998Isolation of human embryonic stem cells.
1999Expert group formed chaired by Chief Medical Officer, Sir Liam Donaldson.
2000Sir Liam Donaldson’s report published, including nine recommendations, including to continue embryonic stell cell research for therapeutic purposes.
2001January: Human Fertilisation and Embryology (Research Purposes) Regulations passed, extending the scope of the 1990 Act.
2001December: Legislation passed to ban any attempts at human cloning. Human Reproductive Cloning Bill passed on 4 December.
2002February 13: House of Lords Select Committee publishes report endorsing Government approach to stem cell research.
2002March 1: HFEA issues two licenses to begin research on embryonic stem cells.
2002July: Government responses to the House of Lords Select Committee on stem cell research.
2002December: House of Lords debate on stem cell research.
2004February: Report from South Korea of first stem cell lines generated from cloned human embryos.
2004May: UK Stem Cell Bank officially launches at the National Institute for Biological Standards and Control (NIBSC) in Hertfordshire. Two embryonic stem cell lines created in the UK are deposited in the new bank.
2004August: HFEA grants the first UK licence for therapeutic cloning to the Centre for Life, Newcastle upon Tyne.
2005February: HFEA grants second licence for therapeutic cloning to Roslin Institute, Edinburgh.


In 1984 the Report of the Warnock Committee recommended that human cloning should not be permitted.  However current legislation in the UK concerning human cloning is somewhat ambiguous. Whilst the law in its current form does not allow any form of reproductive cloning to be licensed, there is no explicit ban on embryo cloning.  In 1999, in answer to a question in the House of Lords the official UK Government position was that “human reproductive cloning is ethically unacceptable and cannot take place in this country”4. Furthermore, the replacement of an embryo, or any cell that is a part of an embryo is also specifically prohibited.  The nuclear replacement of an egg (such as in the process which led to the creation of Dolly the sheep) and embryo splitting are currently allowed in human embryos under the jurisdiction of the Human Fertilisation and Embryology Authority (HFEA) but only for short-term experimental use.  Embryo splitting purely for treatment purposes is not approved by the HFEA, and the UK Government stated clearly in 1999 that “it will not licence cloning by embryo splitting for treatment purposes”5. As laid out in the Human Fertilisation and Embryology Act 1990, the HFEA also regulates the current legislation which allows embryos up to 14 days old to be destroyed, frozen or researched on for specific purposes.   In 1998, in order to consider and explore the ethical issues and possible applications of human cloning, the UK Government asked the HFEA and the Human Genetics Advisory Commission (now called the Human Genetics Commission) to undertake research into these issues and present a report on their findings. The conclusions of this project were published in the report Cloning Issues in Reproduction, Science and Medicine. The recommendations from this report stated that no human reproductive cloning should be allowed but that therapeutic cloning should be allowed6In June 1999, the government decided more evidence was needed on the potential benefits to human health from therapeutic cloning before legislation could be introduced. An independent advisory group was set up, chaired by the Chief Medical Officer Dr Liam Donaldson. The group reported a year later in August 2000.  The key recommendations of the report were as follows7
  • That research using embryos (whether created by in vitro fertilisation or cell nuclear replacement) to increase understanding about human disease and disorders and their cell-based treatments should be permitted”. In order for this to occur, it would require an extension to the HFEA Act of 1990 which currently only allows research for other, limited purposes.
  • Reproductive cloning should remain a criminal offence.
  • It may be required that a further Act of Parliament be created so that new embryo research may be used in treatment of patients.
  • The mixing of human adult cells with the live eggs of animals should not be permitted.
The Government’s response was to accept fully all recommendations made by the group. It was reported that legislation would be brought forward where necessary in order to implement the recommendations.  The Human Fertilisation and Embryology (Research Purposes) Regulations were debated and passed by the House of Commons on December 19, 2000 and the House of Lords on January 22, 2001.  Contained within the new regulations were three new purposes for embryonic research which were added to the original five in the 1990 Act. They were as follows:
  • Increasing knowledge about the development of embryos
  • Increasing knowledge about serious disease, or
  • Enabling any such knowledge to be applied in developing treatments for serious disease8.
The Pro-Life Alliance sought a judicial review at the High Court in response to this, declaring that an embryo created by cell nuclear replacement does not fall within the definition of embryo in the 1990 Act. They won their case in November 2001.  In response, the Government immediately sought to bring in primary legislation to cover cell nuclear replacement and similar techniques. The legislation also outlawed any attempts at reproductive cloning. The Human Reproductive Cloning Act was passed on December 4, 2001. Following the Pro-Life Alliance challenge, the Governement succesfully appealed against the ruling of the lower court in the Court of Appeal.  The earlier ruling was overturned and as a result embryos created by cell nuclear replacement were now considered to be within the scope of the 1990 Act9. Despite given leave to appeal to the House of Lords, the Pro-Life Alliance’s appeal was dismissed in April 2003.  In March 2001, the House of Lords agreed a motion appointing a committee "to consider and report on the issues connected with human cloning and stem cell research arising from the Human Fertilisation and Embryology (Research Purposes) Regulations"10.  The committee’s report (published on 27 February 2002) endorsed the Government position on stem cell research. In July 2002, the Government's response to the report was issued and the report was debated in the House of Lords on December 5, 2002. 

In August 2004, following a decision by the HFEA, scientists at Newcastle University became the first researchers in the UK to be granted permission to clone human embryos for medical research11.  This was followed, in February 2005, by a further such licence issued to scientists at Edinburgh’s Roslin institute12.


Arguments for the use of research cloning13

  • Research cloning may lead to new therapies for diseases.  Some scientists claim that cloned embryos are required in order to obtain embryonic stem cells, which in turn promise to bring through much needed and significant breakthroughs in medicine.  Embryonic stem cell research has the potential to lead to new therapies for many diseases as well as to create genetically modified tissues and organs for transplant and the treatment of degenerative conditions.  However embryos for research and for the generation of stem cells may be obtained from other sources including in vitro fertilisation.

  • The chance to generate immunocompatible tissue and organs for  transplant.  There is a major shortage of suitable genetically matched tissue and organs for transplant.  Research cloning has the potential to create genetically compatible tissues and organs for patients with a minimal risk of immune rejection.  Stems cells obtained from cloned embryos produced from the patient’s own somatic cells, could be used to create the compatible tissue or organ. The frustrations, delays and treatment failures currently experienced by potential recipients could be overcome by way of research cloning.  On the other hand it has been suggested that research cloning may not provide the best or preferred option of overcoming immune rejection. Whilst it is acknowledged that following transplantation, embryonic stem cells appear less likely to stimulate rejection, it is possible that stem cells from other sources could be developed with less inherent potential to induce immune rejection. Similarly it seems unlikely that sufficient human eggs would be available to enable genetically identical stem cells to be generated for the large number of patients who require transplants.

  • Significant advances in basic medical science.  Because of the enormous scientific potential of embryonic stem cell research, it is inappropriate to impose excessive restrictions that could inhibit or postpone scientific or medical advances.  Medical technology has benefited our lives immensely and as a society we must pursue scientific and medical progress with the minimum of unnecessary restriction.

  • The harm of embryo manipulation and destruction does not outweigh the benefit to be gained by research.  If a simple balancing of benefits and harms of cloning research is undertaken, it is argued that the harm suffered by a number of microscopic embryos who have no awareness cannot outweigh the benefit of a range of potential therapies for many suffering humans. 

Arguments against the use of research cloning14

The arguments against research cloning divide into those that are based on principled objection to the procedure itself, and those which highlight possible adverse consequences for society as a whole. Principled objections to research cloning include: 
  • Manipulation and destruction of human embryos is wrong in itself. Human beings go through many stages of development.  There are embryonic humans, fetal humans, neonatal humans, adult humans and elderly humans.  An embryonic human deserves a much moral respect and protection as human beings at other stages of their development.  
  • Instrumentalisation of human beings.  Cloning represents the creation of a human embryo as an instrument of another human’s will and purposes.  It reflects a view of embryonic humans as objects that can be tailor-designed and manufactured to meet certain characteristics and specifications15.
  • The child as a reflection of the love between a man and a woman.  In orthodox Christian thinking, human procreation is seen as indissolubly linked to the committed love of a man and a woman.  In other words “making love” and “making babies” belong together and every child should be a reflection of a love relationship.  Cloning is an asexual form of human reproduction and the creation of a cloned embryo represents an attack on the dignity of human beings. 

Arguments about the consequences of research cloning include:

  • Reproductive cloning becomes ultimately more likely. As research cloning develops as a procedure the techniques of cloning human embryos will be perfected.  It is a very small step to insert this embryo into a human womb to lead to the birth of a cloned child.  Comprehensive, stringent and diligent regulatory oversight and control is required in order that cloned embryos created in laboratories do not end up being used for reproductive purposes.  International regulatory bodies and processes are inadequate to this task and hence reproductive cloning is ultimately inevitable.
  • Research cloning will lead to other reproductive and genetic procedures. As embryo cloning and manipulation techniques are improved it is inevitable that even more powerful human reproductive and genetic modification technology will become feasible.  Again the inadequacies of international regulatory bodies and processes will become critical.
  • The establishing of a market for women’s eggs and manipulation and abuse of women. The proposed therapeutic uses of cloning techniques would require many thousands or millions of women’s eggs a year.  Since there is a very significant medical risk associated with egg donation, the demand for eggs could generate a exploitative market which puts vulnerable women at risk.  In particular, women in countries which do not provide strong legal protection, may be exposed to coercive and exploitative pressures.


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References & Links

  1. Center for Genetics & Society (2003), Reproductive Cloning: Basic Science, [accessed 23rd January 2007]. 
  2. Center for Genetics & Society (2003), Research Cloning: Basic Science,  [accessed 23rd January 2007]. 
  3. Data taken from Department of Health, Stem cell research: Medical progress with responsibility: [8] Key milestones in stem cell research, 15th April 2005, [accessed 23rd January 2007] 
  4. Reply to House of Lords Written Parliamentary Question tabled by Baroness Gould of Potternewton and answered by The Parliamentary Under-Secretary of State, Department of Trade and Industry (Lord Sainsbury of Turville), 24 June 1999, col 106,[accessed 23rd January 2007]. 
  5. Baronness Hayman, House of Lords debate on Human Embryos and Cloning, 28th April  1999, col 350, [accessed 23rd January 2007] 
  6. HFEA and Human Genetics Advisory Committee report, Cloning Issues In Reproduction, Science And Medicine (Issued December 1998), paras 9.2 and 9.3 [accessed 23rd January 2007] 
  7. Department of Health, Stem cell research: Medical progress with responsibility, 15th April 2005, [accessed 23rd January 2007] 
  8. Department of Health, Stem cell research: Medical progress with responsibility (April 2005), Outcomes of the Report, section 6, accessed 23rd January 2007] 
  9. Ibid.  
  10. Ibid.  
  11. Guardian, August 11th 2004,,,1280916,00.html
  13. Center for Genetics and Society (2004), Research Cloning: Arguments,   [accessed 23rd January 2007]. 
  14. Ibid.  
  15. The President’s Council on Bioethics, The Ethics of "Reproductive" Cloning:
    Child, Family, and Society, (Staff Working Paper, February 2002),  [accessed 23rd January 2007]