This fully updated volume serves as multidisciplinary compendium of approaches and techniques employed to analyze the role of different molecules, processes, or strategies used by different guests to survive and proliferate in their associations with eukaryotic hosts. Beginning with animal-pathogen interactions, the book then continues with chapters exploring virus-host interactions, plant-microbe interactions, as well as different molecular techniques that were initially applied to non-pathogenic interactions but can be adapted to study other host-pathogen associations. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step and readily reproducible laboratory protocols, as well as tips for troubleshooting and avoiding known pitfalls.