Patients undergoing transplant operations could be given artificial blood produced from stem cells within the next decade, researchers claim.According to the report on the Daily Telegraph newspaper today, clinical trials using blood created from adult stem cells are set to begin within the next two or three years, raising the prospect it could soon become routinely used where real blood is unavailable.Scientists are also developing alternative bloodlike substances which could be injected into the body as a "stopgap" until an actual blood transfusion could be performed.About two and a half million units of blood are given to patients in Britain every year, costing about £130 each, and modern doctors have minimised the risk of patients receiving infections such as Hepatitis A and C during transmission.But new infections such as vCJD, the human form of mad cow disease, remain a risk and there are also concerns blood becomes less effective the longer it is stored.Blood produced from stem cells would avoid these risks and could be manufactured as type "O-negative", which is produced by just 7 per cent of the population but is suitable for use in into up to 98 per cent of patients.While it would be an imperfect substitute for real blood and therefore not be used in all operations, artificial blood could revolutionise treatment in ambulances, war zones, disaster areas, experts saidIt could also be used in certain hospital situations, for example in elective surgery, and save hundreds of thousands of lives in parts of the world where blood banks are not available.A team at Edinburgh University has developed a method of taking adult stem cells from bone marrow and growing them in the laboratory to produce cells which look and act almost identically to red blood cells.Once their technique is fine-tuned the team may consider using stem cells taken from embryos, or reprogrammed skin cells, instead of adult cells because although the end product does not mimic red blood as closely, they can be grown in much greater quantities in the lab.Prof Marc Turner said: "I think it will probably be two or three years before we get to clinical trials and I would think it will be a decade or so before one sees these kinds of artificial red cells or cultured red cells in routine general practice."A more radical solution, which Essex University researchers say could be perfected within five to 10 years, is to develop a completely artificial alternative to blood which performs the same key functions and would be safe to use in patients of every blood type.This could involve packing haemoglobin – which carries oxygen around the body – into a synthetic cell-like structure, or using a chemical to hold the haemoglobin together so that it can be injected without the need for red blood cells.One artificial substitute based on cows' blood is already licensed in Russia and South Africa, but despite being developed in America it was rejected by the country's drug authorities as unsafe after trials showed it raised the risk of stroke, heart problems and pancreatitis.