What are stem cells?

Listed below are a few common questions that we have been asked in regard to stem cells. If your question isn't answered here then please get in touch with us and we would be more than happy to help.


What are stem cells?

Stem cells are capable of dividing to produce more of themselves and to produce other specialised cell types that an organism needs to develop and live.

In the adult, they can replenish cells that have died due to disease or injury. The process by which a cell changes from one type to another is called ‘differentiation’.

Cells that have acquired their final function are said to be ‘differentiated’. Initially, stem cells are said to be ‘undifferentiated’.

Where are stem cells found?

In a mammalian embryo a few days old, a small group of cells called the ‘inner cell mass’ is formed. These master stem cells give rise to the main cell types of the body.

Embryonic stem (ES) cells are produced from the inner cell mass in the laboratory. Throughout development, different stem cells are formed that produce the specialised tissues and organs. The blood and skin contain stem cells that are constantly replenishing cells lost or dying.

In other tissues, stem cells are much rarer. We are trying to identify and purify stem cells in various tissues.

What are the different types of stem cell?

Stem cells can be classified according to their source (embryonic, foetal and adult), the tissue type (eg blood, neural, skin) and what biologists call potency.

Potency is how flexible a stem cell is at producing the differentiated cell types. Stem cells are said to be ‘pluripotent’ if they can produce many cell types. ES cells are the most pluripotent stem cells.

What are pluripotent stem cells?

Pluripotent stem cells differentiate to form many different cell types. In mice, ES cells grown in the laboratory can give rise entirely to a new offspring showing that they are fully pluripotent. Recently it has been shown that adult cells can be turned into cells that resemble ES cells. These cells are called induced pluripotent stem (iPS) cells.

Why do we want to use stem cells?

We study stem cells so that in the future we may be able to regenerate cells and tissues to treat degenerative diseases and injuries.

Stem cells offer the possibility of developing more accurate methods to discover and test drugs. We can also use stem cells in the laboratory to study early human development which is otherwise inaccessible due to practical or ethical restrictions.

The ability to create induced pluripotent stem cells (iPS) cells opens up the possibility of creating cells directly from patients that suffer from a disease. Growing large numbers of these cells allows us to study the disease process in a dish.

What are the regulations governing ES cells research in the UK?

Research Ethics are overseen by the Human Fertilisation and Embryology Authority (HFEA), the Medical Research Council (MRC) steering Committee and the National Research Ethics Service (NRES).

Our clean room derivation unit is licenced by The Human Tissue Authority (HTA), the UK competent authority for the European Tissue and Cell Directive. Our licence allows the storage, testing and processing of hESC for potential therapeutic application.

How can I access stem cell lines?

To access stem cell lines, researchers in both the UK and abroad will need to apply to the MRC’s UK Stem Cell Steering Committe in the first instance.

Once approval is met, a Material Access Agreement (MAA) will need to be completed with the UK Stem Cell Bank, and a Material Use Licence (MUL) with the owner/depositor of the cells.

It is advisable to begin the process of completing the MAA and MUL whilst the application is under review with the Steering Committee in order to expedite the process.

Which Sheffield derived lines are available from the UK Stem Cell Bank?

Here in the Centre for Stem Cell Biology, we have a number of research and clinical grade Stem Cells line's that are available from the UK Stem Cell bank. Each line's availability is outlined below: 

  • Currently, our research lines Shef 3 and Shef 6 are available from the UK Stem Cell Bank.
  • Our clinical grade lines MasterShef 1, 2, 3, 4, 5, 6, 7, 8 have been approved by the Steering Committee for storage and distribution by the Bank and will be released for application shortly.
  • Our clinical grade lines MasterShef 10, 11, 12, 13, 14 have all been deposited in the bank, more information will be added shortly.
  • Our clinical grade lines Shef 3.2 and Shef 6.1 are also deposited with the bank, more information will be added shortly.

For any further information on any of our cell lines please either contact us or visit the UK Stem Cell Bank website: 

Visit the UK Stem Cell Bank website

Do you run clinical trials?

The Centre for Stem Cell Biology is unable to offer specific advice about the effectiveness of a stem cell treatment.

We recommend that people consult websites from reputable stem cell organisations such as the International Society for Stem Cell Research’s website 'a closer look at stem cell treatments' which offers advice for patients considering a stem cell treatment.

For information relating to clinical trials refer to the MHRA (Medicines and Healthcare Products Regulatory Authority) and for patients interested in clinical trials visit the NIHR (NHS National Institute for Health Research) and the NIH (National Institutes for Health) USA.

For commercial information about stem cell processing in our facility, please contact us.

Do you run training courses?

Yes, please see our training opportunities and information page.

Additional information

For further information, or if your question has not been answered above, please feel free to contact us on stemcell@sheffield.ac.uk.

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