The primary goal of this project is an understanding of collagen structure from the molecular to the fibril level. Emphasis is presently on two main aspects of the general problem. 1) Computer enhancement and reconstruction of electron micrographs to reveal detail not obvious to the eye. 2) Three-dimensional computer models to study and illustrate structural features of collagen and molecular aggregates. Each of the above two approaches has led to the development of computer software that is being applied to other problems in protein structure and electron microscopy. A third aspect of this project, to relate amino acid sequence of collagen to higher level structure, has been inactive this year.