contributed helpful discussions and information on recent developments in x-ray instrumentation. This book was written while one of the authors (CS) was a Visiting Professor at Washington State University in Pullman. We are both obliged to Professor Stephen Antolovich, Director of the School of Mechanical and Materials Engineering at Washington State University, for fadlitating our collaboration and for providing an environment wherein we could complete this book. And last, but by no means least, we would like to thank our wives Meena and Christine. Their presence provides us with an invisible staff that makes the journey easier. It is to them that we dedicate this book.

Exosomes play a significant role in cancer progression and are potentially useful biomarkers for noninvasive diagnostics and therapeutic treatments. Although exosomes are difficult to study because of their small, inconsistent sizes and challenging purification processes, new micro- and nanotechnologies have been recently developed that seek to overcome these limitations. In this review, we examine and compare isolation and detection techniques for various types of extracellular vesicles (EVs) including exosomes, which have sizes <200 nm and microvesicles (MVs), which are >200 nm. Various microfluidic devices that offer better EV purity, higher recovery rates, lower costs, decreased isolation times, and low sample volumes compared to conventional techniques are described with an emphasis on the importance of micro- and nanobased technologies to isolate and detect EVs for the point-of-care acquisition and diagnosis of cancer.

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GGAs, a class of monomeric clathrin adaptors, are involved in the sorting of cargo at the trans-Golgi network of eukaryotic cells. They are modular structures consisting of the VHS, the GAT, hinge, and GAE domains, which have been shown to interact directly with cargo, ARF, clathrin, and accessory proteins, respectively. Previous studies have shown that GGAs interact with clathrin both in solution and in the cell, but it has yet been shown whether they assemble clathrin. We find that GGA1 promoted assembly of clathrin with complete assembly achieved when one GGA1 molecule is bound per heavy chain. In the presence of excess GGA1, we obtained the unusual stoichiometry of five GGA1s per heavy chain, and even at this stoichiometry the binding was not saturated. The assembled structures were mostly baskets, but ϳ10% of the structures were tubular with an average length of 180 ؎ 40 nm and width of ϳ50 nm. The truncated GGA1 fragment consisting of the hinge؉GAE domains bound to clathrin with similar affinity as the full-length molecule and polymerized clathrin into baskets. Unlike the fulllength molecule, this fragment saturated the lattices at one molecule per heavy chain and assembled clathrin only into baskets. The separated hinge and GAE domains bound much weaker to clathrin than the intact molecule, and these domains do not significantly polymerize clathrin into baskets. We conclude that clathrin adaptor GGA1 is a clathrin assembly protein, but it is unique in its ability to polymerize clathrin into tubules.