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Therapeutic cloning:

How it is done; possible benefits

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bullet "Somatic cell nuclear transfer (more commonly called therapeutic cloning) is about saving and improving lives. It is fundamentally different from human reproductive cloning; it produces stem cells, not babies." U.S. Newswire 1
bullet "...[medical] methods that fail to respect the dignity and value of the person must always be avoided. I am thinking in particular of attempts at human cloning with a view to obtaining organs for transplants: these techniques, insofar as they involve the manipulation and destruction of human embryos, are not morally acceptable, even when their proposed goal is good in itself."  Pope John Paul II in an address before International Congress on Transplants on 2000-AUG-29. 2

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What is Cloning?

Cloning is the production of one or more individual plants or animals (whole or in part) that are genetically identical to an original plant or animal. 

Three very different procedures have been referred to as "cloning." Two are:

bullet Adult DNA cloning (a.k.a. cell nuclear replacement): This involves removing the DNA from an embryo and replacing it with the DNA from a cell removed from an individual. Then, the embryo would be implanted in a woman's womb and be allowed to develop in to a new human whose DNA is identical to that of the original individual. This method has been used to clone a sheep. The initial steps of the procedure were tried using human DNA in 1998-DEC. Adult DNA cloning cannot ethically be used to produce a human clone, because experiments on animals have sometimes produced defective specimens. 
bullet Therapeutic cloning: (a.k.a. Somatic cell nuclear transfer or research cloning): This starts with the same procedure as is used in adult DNA cloning. The resultant embryo would be allowed to grow for perhaps 14 days. It's stem cells would then be extracted and encouraged to grow into a piece of human tissue or a complete human organ for transplant. The end result would not be a human being; it would be a replacement organ, or piece of nerve tissue, or quantity of skin. The first successful therapeutic cloning was accomplished in 2001-NOV by Advanced Cell Technology, a biotech company in Worcester, MA.

Unfortunately, although adult DNA cloning and therapeutic cloning are quite different procedures leading to very different goals, both terms contain the word "cloning." This causes a great deal of confusion among the public. Many transfer their disgust at the concept of creating cloned babies to therapeutic cloning whose goal is to create an organ to heal people. Orrin Hatch (R-UT), a pro-life senator has suggested the term "somatic cell nuclear transfer" to replace therapeutic cloning. 3

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How is therapeutic cloning done?

I once had a Swedish ivy plant, and about a dozen empty flower pots. I cut off many leaves from the original plant, placed each of them in a pot filled with damp soil, and surrounded the pots with clear plastic. In a few weeks, I had a dozen new plants. This shows that all of the material and information needed to create a Swedish ivy plant is contained in a single leaf. Actually, it is contained in a single cell of a single leaf.

So too, all the information needed to create a new human being is contained in each cell of an existing human being. DNA testing on an human often starts by scraping some cells from the inside of a person's mouth. Living cells can be scraped off of a person's skin. No matter how a cell is obtained, it contains the DNA of the person, and thus contains all of the information required to produce a duplicate or cloned person. Each cell is, in fact, a form of human life for the simple reason that it contains human DNA.

A woman's ovum also contains her DNA. What is involved in somatic cell nuclear transfer is to:

  1. Take a woman's ovum, and remove its DNA. This converts it to a form of human life into what is basically a factory for creating a pre-embryo.
  2. Remove the DNA from a cell taken from a human, and inserting it into the ovum.
  3. Giving the resulting ovum an electrical shock to start up its embryo making operation. In a small percentage of cases, a pre-embryo will be formed.
  4. The pre-embryo is allowed to develop and produce many stem cells. So far, the procedure is identical to that used in adult DNA cloning. However, the pre-embryo is not implanted in a woman's womb in order to try to produce a pregnancy.
  5. Stem cells are removed from the pre-embryo; this results in its death.
  6. The stem cells would be encouraged to grow into whatever tissue or organ is needed to treat the patient. Stem cells are a unique form of human cell that can theoretically develop into many organs or body parts the body. 
  7. The tissue or organ would be transplanted into the patient. 4

An important factor to remember is that:

bullet The original seed cell is a form of human life; it contains human DNA, whether it comes from a skin scraping or is extracted from the inside of a person's mouth.
bullet The original ovum is a form of human life; it contains human DNA.
bullet The pre-embryo that is produced is a form of human life; it contains human DNA.

So, there is a continuity of human life from a surplus cell which a human produces by the millions each day, to the pre-embryo.

Theoretically, these stem cells can be used to develop into replacement organs (heart, liver, pancreas, skin, etc) Therapeutic cloning has not yet been accomplished in the laboratory or clinic.

Future experiments may not succeed. There were four main hurdles to overcome:

bullet Stem cells have to be "successfully isolated and grown in the laboratory." This has already been accomplished
bullet They have to be encouraged to "turn into specific cell types." This has been done for most of the 220 cell types in the human body.
bullet They have to be proven usable in treating patients with diseases, injuries, or disorders.
bullet The transplanted tissue must develop normally and must not represent significant "risks to the patient." 4

If scientists are successful, it would probably take many years of research before the first useful results will be obtained. 

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What are its possible benefits?

If therapeutic cloning using embryos is successful, then perfectly matched, replacement organs could become freely available to sick and dying people. That would save countless numbers of lives, and increase the quality of life of countless others. Three possible examples of therapeutic cloning "might include the use of insulin-secreting cells for diabetes; nerve cells in stroke or Parkinsonís disease; or liver cells to repair a damaged organ." 4 There would probably also be side benefits resulting from the research. "Further advances in understanding of how organs regenerate would increase the range of possible treatments that could be considered." 4

In the United States during 1998, "More than 50 disease advocates and scientific societies, representing such concerns as diabetes, blindness, Parkinson's disease, glaucoma, AIDS, Down Syndrome, cystic fibrosis, stroke, lymphoma, infertility and cancer--as well as professional groups that focus on such issues as cell biology, aging, microbiology, ophthalmology, cardiology, pediatrics and reproductive medicine--recently sent a letter to members of Congress urging them to support federal funding for...[stem cell] research." 5

This procedure would have a number of advantages, when compared to regular organ transplant donated by a second person: 

bullet There would be presumably be no danger of rejection of the transplant because the organ's DNA would match the patient's DNA exactly. 
bullet For transplants involving kidney (or theoretically any other organ that is duplicated in the body), another individual would not have to experience pain, inconvenience, and potentially shortened life span in order to donate the organ.
bullet The patient would not have to wait until an unrelated donor dies to obtain a transplant. A new organ could be grown for them as needed.
bullet The patient would not have to make-do with a replacement organ that is old and may have reduced functionality; a brand-new organ would be grown specifically for them.
bullet The procedure would save lives which would otherwise be lost waiting for a transplant that did not come in time.
bullet The potential exists to cure, or at least treat, certain diseases and disorders that cannot be effectively handled today.

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What are the problems of therapeutic cloning:

Before therapeutic cloning can become generally available to cure heart disease, diabetes, paralysis, etc., a number of hurdles have to be overcome:

bullet Developing cures: Methods have to be developed that will cure or treat diseases with embryonic stem cells. This looks promising. Research with adult stem cells, which has been underway for many years, have shown great promise. Unfortunately, adult cells are limited in their application. Research using therapeutic cloning is a new field, but it has already shown that stem cells from embryos have much greater flexibility than adult stem cells.
bullet Is an embryo a human person? Pro-life supporters generally believe that a human person comes into existence at conception. Some believe that somatic cell nuclear transfer is sufficiently similar to normal conception with an egg and spermatozoa that a human person also comes into existence during therapeutic cloning. The process of extracting stem cells involves killing the embryo. To many pro-lifers, this is murder. They feel that murdering one person, the embryo, to cure another person of paralysis, or diabetes, or heart disease, etc. can never be justified. More details. Therapeutic cloning research may well be limited to those countries, like China, the UK, and perhaps Canada, where pro-life supporters are relatively few in number.
bullet Stability of stem cells: As of 2003-MAR, therapeutic cloning is still in its early stages of development. Stem cells have sometimes mutated, and thus been rejected by the recipient's body. In other cases, at least with experiments on animals, they have produced tumors. It is obvious that therapeutic cloning will not be feasible until these deficiencies have been overcome.
bullet Where would the eggs come from? At the present stage of somatic cell nuclear transfer, Thomas Okarma, chief executive of Geron Corporation -- a leading stem-cell research establishment -- estimated that takes "100 eggs if you're lucky" to produce a useable stem cell line. 6 This means that if a cure for diabetes involving therapeutic cloning is found, it would take 1.5 billion eggs to cure the 15 million Americans who have diabetes. Until the production of stem cells becomes more efficient, very few cures could be made for economic reasons. Even if and when techniques are found to reliably produce one custom stem cell line for each egg harvested from a woman, 15 million eggs would be required to completely wipe out diabetes. Extracting eggs from women is "painful, costly and unreliable." 7Focus on the Family, a Fundamentalist Christian group, cited an unknown expert who has said that the process of harvesting eggs would seriously injure about one percent of all female donors. 8 We have been unable to determine what form this injury might take. Assuming two dozen eggs per woman, this would still require over a half million women willing to donate eggs and run the risk of some type of injury. Therapeutic cloning will probably only become generally useful when a method is found to use non-human eggs as source material. Research is underway to use rabbit eggs. During the process, "the embryo will lose all traces of its rabbit origin." 7

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Related essay on this website:

bullet Menu: Cloning - all aspects 
bullet Stem cell research

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  1. Julie Kimbrough, "New Poll Shows More Than Two Thirds of Americans Support Therapeutic Cloning Research to Produce Stem Cells," Coalition for the Advancement of Medical Research, at:
  2. Pope John Paul II, "Address to International Congress on Transplants," 2000-AUG-29, at:
  3. Julie Rovner, " 'Therapeutic' Cloning Wins Key Ally in U.S. Senate," Reuters, 2002-APR-30, at:
  4. "A report from the chief medical officer's expert group reviewing the potential of developments in stem cell research and cell nuclear replacement to benefit human health," Department of Health (UK), at: The report is available as an executive summary or as full report in PDF format. You can obtain a free software to read PDF files from Adobe.
  5. "Comment: Stem Cell Research," Mary Woodard Lasker Charitable Trust, at:
  6. Cited in "Testimony of James Kelly before the House Government Reform Committee (Subcommittee on Criminal Justice, Drug Policy, and Human Resources)" on 2002-MAY-15, at:
  7. Charles C. Mann, "The First Cloning Superpower: Inside China's race to become the clone capital of the world," at:
  8. Stuart Shepard, "Cloning Research Found to Hurt Women," Focus on the Family, 2003-MAR-28, at:

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Copyright © 2000 to 2005, by Ontario Consultants on Religious Tolerance
Originally published: 2000-AUG-17

Last updated 2005-OCT-29
Author: B. A. Robinson

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