Pennsylvania, as seed funding. Once they found a candidate dye, they attached the positron-emitting fluorine-18, a radioactive isotope with a half-life of nearly two hours that is used annually in two million PET scans and that can last for as long as a day when prepared in the morning by cyclotron. The dye had been developed and patented by the University of Pennsylvania and was licensed by Avid. Initial tests in 2007 on a patient at Johns Hopkins University Hospital previously diagnosed with symptoms of Alzheimer's disease detected plaque in a PET scan in areas where it was typically found in the brain. Further tests found that the scans detected plaque in patients with Alzheimer's, didn't find it in those without the diagnosis and found intermediate amounts in patients with early signs of dementia. The tests found amyloid plaque in 20% of its test patients over age 60 that had been in the normal range, but had performed worse than a control group on tests of mental acuity. Validation by autopsy In order to confirm if the dye was accurate in detecting Alzheimer's, an advisory committee at the Food and Drug Administration demanded that the team of Avid, Bayer and General Electric perform a study to test their method. Avid established a study with a group of 35 hospice patients, some that had been diagnosed with dementia and others that had no memory problems. The participants and their families agreed that they would undergo the PET scans and would have their brains autopsied after their death by pathologists. After the study was conducted, Avid received confirmation in May 2010 that the results of the test were successful in distinguishing between those with Alzheimer's and those without the disease. In results presented in July 2010 to an international conference on Alzheimer's disease held in Hawaii, the company showed that for 34 out of the 35 hospice patients who had been scanned, the initial scan results were confirmed when pathologists counted plaque under a microscope and when a computerized scan of the plaque was performed on material from the autopsied brain. The findings will require review by the FDA to confirm its reliability as a means of diagnosing the disease. If confirmed, the technique would provide a means to reliably diagnose and monitor the progress of Alzheimer's and would allow potential pharmaceutical treatments to be evaluated. In a study published in January