A collection of readily reproducible techniques for the study of mRNA processing and metabolism. These cutting-edge techniques range from cotranscriptional processing events that occur while the mNA is engaged with elongating RNA polymerase II, to in vivo and in vitro splicing and its biochemical analysis, and alternative splicing. Additional methods cover mRNA export, the recovery and analysis of mRNP complexes, cytoplasmic translation, mRNA degradation in vivo and in vitro, and the controversial concept of nuclear translation. Each proven protocol is described in step-by-step detail and contains a background introduction outlining the principle behind the technique, lists of equipment and reagents, and tips on troubleshooting and avoiding know pitfalls.