A longstanding question in biology is how biochemical events inside of a complex cellular environment are coordinated to drive a specific biological process. To accomplish this, there is growing support that proteins in cells organize beyond binary complexes to form supramolecular or mesoscale protein assemblies. These higher ordered assemblies manifest anywhere between homo- and hetero-oligomeric structures such as filaments and granules to those that are extremely dynamic and transient such as condensates and metabolic enzyme organizations such as metabolons. This book highlights ongoing research efforts on the structure-function and dynamics of these types of complexes, and emphasizes the importance of protein assemblies across different subcellular compartments and structures. Sections explore membrane receptors and signaling, DNA/RNA complexes, and metabolic enzyme assemblies. Integrated into each of these sections and chapters are different techniques that have been or are currently being used to study these assemblies, with the goal of illustrating how specific technologies have advanced our understanding of these systems. Interest in studying supramolecular protein assemblies has exploded over the past decade with the emergence of biomolecular condensates and metabolons as common modes of cellular regulation. This is an ideal resource for any student or researcher interested in learning more about this up-and-coming area.