In the past several years significant attention has been given to the analysis
of the properties and functions of lateral microdomains (rafts) in biological
membranes. As described in the overview chapter of this book, as well as in the
introductions to many of the other chapters, there are many fundamental unanswered
questions concerning the composition, structure, dynamics, and even the
very existence of these membrane rafts. Therefore, a variety of sophisticated
techniques have been used to study intact cell membranes, as well as model systems
composed of specific lipids and proteins thought to be in rafts. The analyses
of biological membranes have provided detailed data on intact microdomains,
and the complementary studies of model systems have given critical insights on
the roles of specific lipid-lipid and lipid-protein interactions in raft formation
and function.