The NEI Central Transgenic Animal 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 seven laboratories in the NEI (LI, LMDB, LMOD, LOT, LRCMB, OGCSB, OSD); in our program, there are currently 215 DNA constructs which 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 analysis on the mice which are born from these procedures to identify transgene positive mice. At the researchers request, we mate positive transgenic mice, wean litters, biopsy and analyze DNA from successive generations of transgenic mice, provide the transgenic animals to researchers for use in their experiments, and cryopreserve and bank embryos from important mouse lines (both transgenic and naturally occurring) for long term storage. We have recently begun collaborating on gene knockout projects, doing the ES cell injections into blastocysts.This year we have: * accepted 15 new constructs for transgenic mouse production;* generated 40 transgenic founder mice; * set up 448 matings of transgenic mice; * weaned, tagged and tail biopsied 3,266 mice;* isolated DNA from 4,143 samples; performed 5,399 PCR analyses; * injected 6 ES cell lines into blastocysts for generation of chimeric mice. Since the program began in 1991 we have: * accepted 215 transgene constructs * generated over 1,000 transgenic founder mice; * set up over 2,700 matings of transgenic mice; * weaned, tagged and tail biopsied over 28,200 mice;* isolated DNA from 29,127 samples; performed over 34,100 PCR analyses; * frozen approx. 5,800 embryos to preserve 20 mouse lines. * injected 6 ES cell lines into blastocysts for generation of chimeric mice. - Transgenic, cryopreservation, embryos, microinjection, knockout, mice, mouse, service