Could the stem cell 'repair kit' become a reality? Diseases from cancer to Alzheimer's could be cured using a single cell Swedish scientists say they have written the recipe for making ethically acceptable, highly versatile stem cells in large numbers The embryonic stem cells could be banked and turned into treatments for patients who need to replace diseased, damaged and worn out body parts Previously, taking stem cells from embryos resulted in the embryo's death but scientists can now remove just one stem cell meaning the baby survives The dream of using stem cells as a repair kit for diseases from Alzheimer's to cancer is closer to being realised. Scientists say they have written the recipe for making ethically acceptable, highly versatile stem cells in large numbers. The embryonic stem cells could be banked and turned into life-saving treatments for patients who need to replace diseased, damaged and worn out body parts. The dream of being able to use stem cells as a repair kit for diseases from Alzheimer's to cancer is now a step closer to being realised A spokesman for the Swedish research team said: "The discovery is a big step forward for stem cell research and for the high hopes for replacing damaged cells and thereby curing serious illnesses such as diabetes and Parkinson's disease." Stem cells - "master cells" capable of turning into other cell types - are widely seen as a repair kit for the body. Embryonic stem cells, plucked from embryos in the first days of life, are the most versatile and so offer the most promise. However, their use is mired in controversy, because they have to be extracted in such large numbers that the embryo dies. But researchers from Stockholm's Karolinska Institute say they have found a way of safely removing a single, precious stem cell. The method is already used in IVF treatments and so it is known that the remainder of the embryo can still turn into a baby. Lead researcher Karl Tryggvason said: "We know that the embryo can survive the removal of a single cell. This makes a huge ethical difference. Just as importantly, the Swedes have also worked out how to make that lone cell grow and multiply. And they have done all of this without using animal products or human cells that could introduce contaminants, the journal Nature Communications reports. Although stem cells have been grown from a single cell before, scientists have struggled to make the quantities and quality needed for human treatments. Professor Trggvason said: "Using this technology, the supply of human embryonic stem cells is no longer a problem. It will be possible to establish a bank where stem cells can be matched by tissue type, which is important for avoiding transplants being rejected. Another possibility is a single stem cell could be removed from an embryo before IVF treatment and then used to generate tailor-made treatments should that baby become ill later in life. British experts said the breakthrough would be welcomed by those battling devastating diseases but cautioned that the removal of even a single cell from a fledgling embryo is not without risk. Scientists think their discovery could eventually lead to cures for diabetes, cancer, Alzheimer's and Parkinson's disease Dagan Wells, an Oxford University IVF expert, said: "A method capable of providing a reliable supply of stem cells, without harming human embryos, could prove to be a wonderful advance. The method is a promising development, although it probably won't entirely eliminate ethical issues. It is true that a single cell can be removed from very early embryos, but the procedure does carry a small risk that the embryos will not survive. Despite these limitations, the research seems to be on the right track and will undoubtedly be welcomed by patients affected by a wide variety of crippling diseases.