As there are no treatments for prion diseases, animals must be destroyed (cremated) as a means to stop the spread of the diseases to healthy animals. Because there is no simple test for the presence of the diseased prions in animals, thousands of mostly healthy animals were killed in England during the outbreak of Mad Cow Disease in Summer 2001. The impact on farmers and the tourism industry was enormous. The impact on agriculture and animal and human health would be likewise devastating if prions were employed by bioterrorist weapons. This could arise simply by spreading the agent in the water or food supply, and perhaps even just by crop dusting fields of fruits/vegetables destined for animal and/or human consumption. As PrPSc agents can only be deactivated and destroyed by incineration, prions can be effectively used by terrorists as a bioterrorist weapon to kill humans and destroy economies by introducing PrPSc agents into the environment or food chain. Therefore, it is imperative that tests be made available for use ante-mortem in animals and man, as well as for environmental type samples that could lead to human exposure and contamination. Our goal in this project is to develop improved analytical tests for a variety of samples (blood, urine, milk, water, soil, plants, forage, etc.), in order to detect the presence of very low levels of the diseased prion protein (PrPSc) and the presence of the disease before (!) physical manifestations appear. This project will address the development, optimization, and validation of newer trace assays for PrPSc in a wide variety of samples, including those that might be used by bioterrorists as chemical/biological warfare targets.