This book provides methods and clear protocols for the various technologies available to detect, characterize, and study Citrus tristeza virus (CTV), a member of the genus Closterovirus, family Closteroviridae. Thanks to the highly sensitive and specific diagnostic procedures developed, knowledge of the molecular characteristics, expression strategies, genetic variability, and epidemiology of the virus has improved significantly, as this volume reflects. 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, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls.