Results obtained from in vitro experiments often need to be confirmed by in vivo experiments. The study of RNA-protein interactions is no exception. Information on RNA-protein complex formation in the cell is important for understanding the mechanisms of cellular RNA metabolism such as RNA processing and transport. For such purposes,Xenopusoocytes are extremely useful cells thanks to their large size. Interactions of microinjected proteins and RNAs with their binding partners can be examined easily by immunoprecipitation experiments with nuclear or cytoplasmic fractions from microinjectedXenopusoocytes. We describe a method to study how RNAs that have been microinjected into the nucleus ofXenopusoocytes are assembled into complexes with specific endogenous proteins.
