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Frequently Asked Questions (FAQs)

Basic Questions

  1. What are stem cells?


  2. What classes of stem cells are there?
    Stem cells may be pluripotent or multipotent.

  3. Where do stem cells come from?
    There are several sources of stem cells. Pluripotent stem cells can be isolated from human embryos that are a few days old. Cells from these embryos can be used to create pluripotent stem cell "lines" —cell cultures that can be grown indefinitely in the laboratory. Pluripotent stem cell lines have also been developed from fetal tissue (older than 8 weeks of development).




  4. Why do scientists want to use stem cell lines?


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Healthcare Questions

  1. Why are doctors and scientists so excited about human embryonic stem cells?


  2. Have human embryonic stem cells been used successfully to treat any human diseases yet?
    Stem cell research offers hope for treating many human diseases. Click here to read a description of the current status of stem cells and human disease therapies.

  3. What will be the best type of stem cell to use for therapy?
    Pluripotent stem cells, while having great therapeutic potential, face formidable technical challenges. First, scientists must learn how to control their development into all the different types of cells in the body. Second, the cells now available for research are likely to be rejected by a patient's immune system. Another serious consideration is that the idea of using stem cells from human embryos or human fetal tissue troubles many people on ethical grounds.



    It is now possible to reprogram adult somatic cells to become like embryonic stem cells (induced pluripotent stem cells, iPSCs) through the introduction of embryonic genes. Thus, a source of cells can be generated that are specific to the donor, thereby increasing the chance of compatibility if such cells were to be used for tissue regeneration. However, like embryonic stem cells, determination of the methods by which iPSCs can be completely and reproducibly committed to appropriate cell lineages is still under investigation. Since they are derived from adult cells, iPSCs may also suffer DNA abnormalities, as described in the previous paragraph.

  4. I have Parkinson's Disease. Is there a clinical trial that I can participate in that uses stem cells as therapy?
    The public may search a database of NIH-sponsored clinical trials at Enter the search terms of interest (in this case, Parkinson's Disease and stem cells) to search for applicable clinical trials.

  5. Where can I donate umbilical cord stem cells?
    NIH cannot accept donated umbilical cord stem cells from the general public. The National Marrow Donor Program maintains a Web page on donating cord blood at

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Research and Policy Questions

  1. Can a scientist use federal funds to conduct research using derivatives of human embryonic stem cell lines that are not listed on the NIH Human Embryonic Stem Cell Registry?
    No federal funds may be used, either by an awardee or a sub-recipient, to support research using derivatives of human embryonic stem cell lines (hESCs) that are not listed on the NIH Human Embryonic Stem Cell Registry, with the exception described below. Derivatives include, but are not limited to, subclones of hESC lines, modified hESC lines (such as a line expressing green fluorescent protein), differentiated cells developed from hESC lines (such as muscle progenitor cells), and cellular materials (such as DNA, RNA, and proteins).

    Ongoing NIH-supported research involving derivatives of hESC lines that were listed on the NIH Registry before April 17, 2009, is subject to the same policy explained in NIH Guide Notice NOT-OD-09-123 for hESC lines.


  2. Which research is best to pursue?
    The development of stem cell lines that can produce many tissues of the human body is an important scientific breakthrough. This research has the potential to revolutionize the practice of medicine and improve the quality and length of life. Given the enormous promise of stem cell therapies for so many devastating diseases, NIH believes that it is important to simultaneously pursue all lines of research and search for the very best sources of these cells.

  3. Why not use adult stem cells instead of using human embryonic stem cells in research?

  4. What are the NIH Guidelines on the utilization of stem cells derived from human fetal tissue (embryonic germ cells)?
    The Federal Register Announcement National Institutes of Health Guidelines for Research Using Human Pluripotent Stem Cells (230k PDF; get Adobe Reader), published August 25, 2000, was "superceded as it pertains to embryonic stem cell research" on November 14, 2001). However, Section II. B, titled "Utilization of Human Pluripotent Stem Cells Derived from Human Fetal Tissue," still governs human embryonic germ cell research. In addition, Section III, titled "Areas of Research Involving Human Pluripotent Stem Cells That Are Ineligible for NIH Funding," governs both human embryonic stem cell and human embryonic germ cell research.


  5. May individual states pass laws to permit human embryonic stem cell research?
    Individual states have the authority to pass laws to permit human embryonic stem cell research using state funds. Unless Congress passes a law that bans it, states may pay for research using human embryonic stem cell lines that are not eligible for federal funding.


  6. Where can I find information about patents obtained for stem cells?
    The U.S. Patent and Trademark Office offers a full-text search of issued patents and published applications. Try searching for "stem cell" or "stem cells."

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Cell Line Availability and the Registry

  1. I am a scientist funded by the NIH. How many cell lines are available to me, and how do I get them?
    The NIH has developed the NIH Human Embryonic Stem Cell Registry. This Registry lists all cell lines that are eligible for use in NIH funded research.

    The number of lines available for use in NIH funded research continues to expand, as we continue to review new lines that have been submitted for NIH's consideration. Please check the current NIH Human Embryonic Stem Cell Registry page for the most up-to-date list.

    To obtain these cells, please follow the "see details" link, which is found under the Cell Line name, within the NIH Human Embryonic Stem Cell Registry. This link includes more information about the selected cell line, as provided to the NIH. Some of this information may include: whether or not the cell line is available for distribution, the provider's name, telephone number, email address, and URL.

  2. Who owns the cells?
    The stem cell lines remain the property of the individual stem cell providers, as listed on the NIH Human Embryonic Stem Cell Registry. Researchers may negotiate a material transfer agreement (MTA) with the cell providers in order to specify their rights and responsibilities concerning resulting data, publications, and potential patents.

  3. Are there any restrictions on the use of lines listed on the NIH Human Embryonic Stem Cell Registry?
    The "see details" link on the NIH Human Embryonic Stem Cell Registry includes information on two categories of possible use restrictions: Provider Restrictions and NIH Restrictions. Provider Restrictions include things such as experiments that are prohibited with the cell line, or requirements that proposed research be approved by an ESCRO or other type of ethical review committee. NIH Restrictions are imposed on the use of a line based on the usage of the cells as agreed to by the donors in their informed consent process.

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Subclones and Modified hESC Lines

  1. Once a human embryonic stem cell line is listed on the NIH Human Embryonic Stem Cell Registry, are lines derived from it also eligible?
    The NIH Guidelines on Human Stem Cell Research focus on the requirements for donation of the embryo that was used for derivation. Once that determination has been made for a particular line, it applies to all subclones or modifications. For example, now that WA01 (H1) is eligible for NIH funding, WA01 lines that express GFP are also eligible.

  2. Should scientists list the name of the subclone in their NIH grant application?
    Yes, scientists should refer to the parent hESC line and list the cell line name of the modified line or subclone in the research plan of their application.

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