Project Summary/Abstract—Overall The Caenorhabditis Genetics Center (CGC) is the sole comprehensive repository and distribution center for the nematode Caenorhabditis elegans, a premier model organism for biomedical research studies. The overall objective of this animal resource is to promote research on C. elegans by acquiring, maintaining, and distributing genetically characterized nematode stocks. Researchers in all 50 states and throughout the world use genetic stocks obtained from the CGC in diverse basic and applied research endeavors, as well as for hands-on teaching of experimental science. Studies using C. elegans have led to fundamental insights into basic biological mechanisms, including the genetic basis of programmed cell death, the discovery of microRNAs, and the mechanism of RNA interference in animals. The nematode has also provided key insights into the cell signaling mechanisms, cancer progression, and neurodegenerative diseases. In addition, C. elegans serves as a key model for illuminating our understanding of parasitic nematodes with relevance to human and livestock health. As the only general stock center for C. elegans, the CGC is an extremely important international research resource, supporting research in these diverse areas and in educational endeavors. The CGC provides about 30,000 strains per year to thousands of laboratories; with a collection of 23,000 unique strains, a number still increasing in proportion to the growth of the field, the CGC not only facilitates research, but also ensures that valuable strains are preserved. Strains are distributed upon request through an on-line ordering system with a scheme of user fees in place to help defray costs and support CGC activities. The CGC closely monitors user needs and devises small research projects to support the community. Because essentially every lab uses fluorescent proteins, and there is demand for brighter, more photostable fluorescent proteins, in more colors to allow multi-plexing, the CGC will develop a pipeline to quantitatively evaluate the in vivo properties of a new set of fluorescent proteins in worm, enabling scientists to choose the optimal versions for their applications.