This revised application requests funds to purchase a TR19 dual particle cyclotron manufactured by Advance Cyclotron Systems which is necessary to support ongoing and future research growth at Washington University. The combination of features within the TR19 is optimal for supporting the diverse number of PET radionuclides and radiopharmaceuticals needed to support our NIH-funded research. The TR19 which is the only machine suitable to produce a broad spectrum of positron-emitting isotopes including Cu-64, Zr-89, I-124;it is also ideal for increasing the production of "standard" radionuclides such as C-11, F-18, an O-15 required for our clinical imaging studies. The TR19 will be installed in the Department of Radiology at Washington University (WU). WU has ongoing inpatient and outpatient research near this location that offers unique clinical and collaborative research projects. The TR19 will fulfill the long-term objective to increase our ability to support ongoing and future research growth at Washington University by providing a more reliable and flexible platform that will double the radioisotope production capacity of our cyclotron facility. By significantly enhancing our reliability to produce radioisotopes, PET research can continue without concern of complications due to frequent and severe maintenance issues leading to unavoidable downtown and the cancellation of research studies. Unlike the current CS-15 and JSW168 cyclotrons, the TR19 will allow increased efficiency and flexibility for non-standard isotope production as well as improved production capabilities of the standard PET radionuclides.