Cells possess a wealth of posttranscriptional control mechanisms that impact on every conceivable aspect of the life of an mRNA. These processes are intimately intertwined in an almost baroque manner, where promoter context influences the recruitment of splicing factors, where the majority of pre-mRNAs undergo alternative splicing, and where proteins deposited during nuclear processing impact distal cytoplasmic processing, translation, and decay. If there is a unifying theme to mRNA Processing and Metabolism: Methods and Prools, it is that mRNA processing and metabolism are integrated processes. Many of the techniques used to study mRNA have been described in a previous volume of this series (RNA–Protein Interaction Prools, Susan Haynes, ed.) and specialized methods journals. In selecting topics for mRNA Processing and Metabolism: Methods and Prools, I sought input on new and novel techniques and approaches that build on this foundation using technological advances in microscopy, whole genome sequencing, microarrays, mass spectrometry, fluorescent detection methodologies, and RNA interference. I have tried not to bias this book toward any single model organism, and approaches described in the various chapters use yeast, Drosophila, Xenopus, mice, plants, and cultured mammalian cells.