This volume is designed to be a resource of proven techniques and approaches for probing the activities of bacterial, eukaryotic, and archaeal RNA polymerases. This book features a collection of in vitro and in vivo technologies that will permit researchers to purify and probe the position and stability of RNA polymerase complexes at different points of the transcription cycle, analyze the various translocations and intermolecular movements associated with catalysis, define recruitment strategies, probe the roles of transcription factors in each stage of the cycle, highlight conserved and disparate fidelity mechanisms, analyze the resultant transcripts, and study coordination of the nascent mRNA synthesis by the RNA polymerase and mRNA translation by the ribosome. Written in the highly successful Methods of Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and key tips on troubles troubleshooting and avoiding known pitfalls. Practical and timely, Bacterial Transcriptional Controls: Methods and Protocols highlights the breadth and depth of techniques that are likely to continue shaping the transcription community in the future.