Electron Paramagnetic Resonance Investigations of Biological Systems by Using Spin Labels, Spin Probes, and Intrinsic Metal Ions Part A & B, are the latest volumes in the Methods in Enzymology series, continuing the legacy of this premier serial with quality chapters authored by leaders in the field. This volume covers research methods centered on the use of Electron Paramagnetic Resonance (EPR) techniques to study biological structure and function.