The Department of Pathology at Robert Wood Johnson Medical School has a number of established investigators whose work focuses on the determination of biological structure. Areas of current research include: collagen fibril formation and tissue organization, skeletal muscle fibril structure, the structure and assembly of basement membranes and the molecular structure of collagen fibrils. A Bioimaging Program has been created within the Department of Pathology to serve as a center for research into biological structure. At present, this program encompasses the electron microscopy and the image analysis laboratories. These laboratories are capable of performing high resolution electron microscopy, computer assisted reconstructions from electron micrographs and computer processing of electron and x-ray diffraction patterns from film. The creation of this program was coupled with the addition of several new faculty and this expanded research effort in biological structure has saturated our existing electron microscopy facility. We are requesting the funds to purchase a JEOL 1200EX transmission electron microscope with video camera, image intensifier and DEC-IPS video image processing system. This instrument will replace our Philips 300 transmission electron microscope which is incapable of the performance demanded by the high resolution, stereoscopic and analytical work now being done in the Department of Pathology. The JEOL 1200EX video transmission electron microscope with image processing system will contribute substantially to the further development of the Bioimaging program in the Department of Pathology by providing the instrumentation necessary for the coupling of our electron microscopy laboratory with our image analysis and processing laboratory. This instrument will support a variety of ongoing research projects, take advantage of the expertise that the Department possesses and broaden the scope of the structural studies that we can accomplished.