This proposal requests funding for a state-of-the-art digital transmission electron microscope, the Zeiss EM 910. This instrument will serve a growing community of researchers at the University of North Texas Health Science Center at Fort Worth as well as a number of other researchers from local institutions. Currently the electron microscopy lab of the Microscopy Core Facility serves 12 researchers. This includes 5 major projects with the remainder being comprised of minor projects, graduate students and non-Health Science Center researchers. The Microscopy Core of the Health Science Center is housed within the Department of Anatomy and Cell Biology and is currently attempting to upgrade its facilities. Several pieces of state-of-the-art support equipment have already been acquired. The Zeiss EM 910 will replace an aging transmission electron microscope which cannot be upgraded to the levels of sophistication and ability currently needed. The Zeiss EM 910 is a state-of- the-art instrument which will enable us to meet our current and future needs, as well as add an integral piece of equipment to an ongoing effort to improve the research infrastructure at this new health science center.Our current research needs, which the Zeiss EM 910 meets and our present microscope does not meet, include: 1. Improved image contrast for work with low contrast specimens (i.e. immunocytochemistry and in situ hybridization). 2. The ability to record, store, manipulate and print digital images from the transmission electron microscope. 3. The ability to perform morphometry, stereology and particle analysis using digital images. 4. Storage and automated recall of specimen grid coordinates. 5. Low magnification micrography and automated montaging. 6. Enhanced data recording to both negatives and archival computer files. 7. Utilization of the Health Science Center's computer network for exchanging data and images between researchers here an d around the country. 8. Electronic image rotation to allow better orientation of images prior to recording. 9. Future upgradability to cryoelectron microscopy, scanning transmission electron microscopy, energy dispersive x-ray analysis and the in-line Omega electron energy filter. This instrument will also compliment our goal of improved training of institutional and community graduate students and.technicians. It will also enhance the current medical profession program and the planned allied and public health professions programs of this new health science center.