DNA test to tell you how long you'll live set to go on sale for £435 by the end of the year. Medical researchers say they may be able to read someone's 'biological age' by the length of telomeres on the end of our chrormosomes A test that tells you how long you will live for is to go on sale in Britain later this year. The blood test, which will offer the alluring possibility of estimating your lifespan, will cost £435 according to a report last night. Critics said the controversial new technology opens a Pandoras box, whereby insurance companies may demand tests before offering someone a policy. However, scientists said the test could also provide vital insights into a range of age-related disorders, from cardiovascular disease to Alzheimers and cancer. Medical researchers working on the technology said they will be able to read a persons biological age, by the length of structures on the ends of a persons chromosomes, called telomeres. Scientists believe telomeres are an important indicator of the speed at which a person is ageing and several studies have indicated that individuals with shorter-than-normal telomeres are likely to die younger than those with longer telomeres. But the test cannot yet predict the exact number of months and years a person has yet to live. Telomere testing will become widespread within the next five or 10 years, scientists claim. But some medical researchers have already raised questions about ethical controls, if the technology becomes widely used. More... We've found the gene that makes you fat, claim scientists Forever young? Why being a musician can slow effects of ageing Faced with bad news, it is not known how people will react to the test. The results of the tests could also be of great interest to companies offering life-insurance, with those not blessed with long telomeres struggling to get cover. Some scientists are also worried that testing may be hijacked by organisations or individuals trying to peddle fake elixirs of life. The blood test will cost £435 according to a report last night (posed by model) Maria Blasco of the Spanish National Cancer Research Centre in Madrid the inventor of the commercial test said: We know that people who are born with shorter telomeres than normal also have a shorter lifespan, But we dont know whether longer telomeres are going to give you a longer lifespan. Thats not really known in humans. she added. Dr Blasco said that the test was simple, fast and very precise. What is new about this test is that it is very precise. We can detect very small differences in telomere length and it is a very simple and fast technique where many samples can be analysed at the same time. Most importantly, we are able to determine the presence of dangerous telomeres those that are very short. Dr Blascos company, Life Length, is in negotiations with medical diagnostic companies to market the test and collect blood samples for analysis in Spain. Life Length is expecting demand from thousands once the company is able to bring down the cost of the test. Although Life Length is not the only company selling telomere tests, it is the only one gearing up for over-the-counter sales to the public, said Professor Jerry Shay of the University of Texas Southwestern Medical Centre in Dallas. Professor Shay, who is a scientific consultant for Life Length said, This test devised by Blasco is so accurate that it is likely to provide more useful information than some of the other tests out there right now, Everyone talks about the chronological age, but there is also a biological age and telomere length is actually a pretty good representation of your biological age. Telomeres are important there is no question of that.