A collection of standard and cutting-edge techniques for using Xenopus oocytes and oocytes/egg extracts to reconstitute biological and cellular processes. These readily reproducible methods take advantage of the oocyte's impressive protein abundance, its striking protein translation capacity, and its breathtaking possibilities for the assembly of infectious viral particles by single cell injection of multiple RNAs. The authors focus on the versatility of frog oocytes and egg extracts in cell biology and signal transduction, and cover all the major uses of oocytes/extracts as experimental models.