Molecular Characterization of Autophagic Responses, Part A, presents a collection of methods for the qualitative and quantitative evaluation of virtually all the morphological, biochemical, and functional manifestations of autophagy, in vitro, ex vivo and in vivo, in organisms as distant as yeast and man. Autophagy is an evolutionarily conserved mechanism for the lysosomal degradation of superfluous or dangerous cytoplasmic entities, and plays a critical role in the preservation of cellular and organismal homeostasis. Monitoring the biochemical processes that accompany autophagy is fundamental for understanding whether autophagic responses are efficient or dysfunctional.