This award supports an international workshop on modern light microscopy to be held in Mendoza, Argentina from November 12- 18, 1990. The U.S. organizer is Dr. Shinya Inoue of the Woods Hole Marine Biological Laboratory in Massachusetts. His Argentinean counterpart is Dr. Mario Burgos of the National University of Cuyo in Mendoza. The speakers consist of four experienced microscopists from each country, the U.S. and Argentina. Video microscopy is a powerful tool for biology, medicine and materials science. For this reason, this workshop assumes greater importance than just discussions of equipment or techniques. The three general areas to be covered are: (A) foundations of light microscopy, including analysis of image resolution and contrast, impact of illumination, and principles and applications of phase contrast, differential interference contrast, polarization microscopy, confocal imaging, and optical sectioning; (B) fluorescence microscopy, including target-specific probes, instruments, and ratio imaging; and (C) video microscopy and digital image processing and analysis, including video principles, contrast and feature enhancement, noise integra- tion, and examples of applications. The workshop will bring together Latin American and U.S. scientists to explore future collaborations. Also they will share with academic and industrial investigators, including advanced graduate students in Latin America, the forefronts of this emerging field in order to encourage applications in research. The mornings will generally be devoted to lectures and discussions, and the afternoons to laboratory demonstra- tions with extensive opportunities for hands-on experience with modern optical and video equipment. The lecturers are well-experienced, having participated in similar workshops before at the Marine Biological Laboratory, in Woods Hole, Massachusetts.