The scientist in charge of anti-doping at next year\'s London Olympics says the games will be the toughest yet for cheats.Prof David Cowan strongly indicated that a new test to catch blood dopers could be deployed for the first time. Speaking at the British Science Festival in Bradford, Professor Cowan confirmed there would also be a new test for human growth hormone. He said a new lab would aim to carry out about 6,000 tests during the games. While scientists have developed tests for almost all forms of doping in sport, the one that has caused them the most trouble has been the practice of athletes storing and transfusing their own blood. Known as autologous blood doping, it increases the number of red blood cells and gives a substantial boost to an athlete\'s endurance by allowing them to carry more oxygen. Several high profile Olympic competitors have been accused of the practice over the past 30 years, while scientists have failed to develop an effective test.But according to Professor Cowan, who is based at King\'s College London, that might be about to change. At this meeting he gave details of a new test that would compare the age of blood samples by looking at the genetic component of red blood cells.\"We\'re working on a scheme where the nuclear material, not in the nucleus itself, but the RNA material in the cell has been shown to change and we are hoping that using those markers we\'ll be able to distinguish stored blood from blood that\'s in your body naturally,\" he said.Scientists have developed a successful test for another type of manipulation called homologous blood doping. This involves taking blood from relatives or friends of a similar blood group. It was highly prevalent in cycling and winter sports through the 1990s and the early parts of the 21st century. Researchers working with the World Anti-Doping Agency (WADA) succeeded in developing a test based on differences in blood cell surface antigens. It led to the sentencing of cyclist Tyler Hamilton who won a gold medal at the Olympic games in Athens in 2004 but failed a test for homologous blood doping shortly afterwards.In reaction to the introduction of this test, dopers became more reliant on their own blood supplies. In 2006 Spanish police raided a clinic in Madrid run by a Dr Eufemiano Fuentes. The so-called Operation Puerto uncovered a systematic, highly organised doping ring based mainly on storing and transfusing blood. Dozens of cyclists and other athletes were said to have been involved. Now, without directly confirming that the test for autologous doping would be available by next Summer, Professor Cowan gave the strongest hint yet that it would be ready in time. \"I would never guarantee what we can deliver by a particular time, that\'s the nature of research, we\'re working very quickly on this, the progress is very exciting. I would put it the other way round, if you\'re an athlete be careful - we may have a test in time,\" he said. Professor Cowan did confirm that an improved test for human growth hormone would be available next Summer and that tests for gene doping were also in the pipeline. His message to dopers was simple - cheats will be caught if they come to London.