The NEI Central Transgenic Animal Production Facility is a research support facility for all NEI intramural researchers requiring the use of transgenic mice in their research programs. We are currently providing transgenic animal support to researchers from four laboratories in the NEI (Laboratory of Immunology, Laboratory of Mechanisms of Ocular Diseases, Laboratory of Molecular and Developmental Biology, and Laboratory of Retinal Cell and Molecular Biology). In our program, there are currently 84 deoxyribonuclei acid (DNA) constructs that are at various stages of completion. NEI researchers using molecular biology techniques to study the eye submit DNA constructs to our section for production of transgenic mice. We create transgenic mice by standard procedures, then biopsy and perform DNA analyses on the mice that are born from these procedures to identify positive mice. At researchers' request, we mate positive transgenic mice, wean litters, biopsy and analyze DNA from successive generations of transgenic mice, and provide the transgenic animals to researchers for use in their experiments. During the year, we have generated 155 transgenic founder mice from 34 DNA constructs; set up 456 matings of transgenic mice; weaned, tagged, and tail-biopsied 4,527 mice; isolated DNA from 4,708 samples; and performed 4,912 DNA analyses. This year we began an embryo cryopreservation and banking program to provide long-term storage of important transgenic lines without the need to maintain live mice. A total of 1,326 embryos from five transgenic lines have been frozen. In addition to service functions, we also collaborate with NEI researchers on transgeni animal projects.