This book examines in depth the theory instrumental innova- tions potential applications and limitations of the different techniques -- NMR EPR DSC spectrofluorimetry and electron microscopy -- that are being used to investigate the function and structure of biological membranes and their model systems. Pro- viding an overview of the present status of research this book gives evidence of the complementary nature of information generated by different techniques reminding one of the necessity to create a common language and viewpoint of membranes. F. Conti W. E. Blumberg J. De Gier F. Pocchiari v CONTENTS Physical methods on biological membranes and their model system: A perspective . - - - - - . - - - - - - . - 1 F. Conti J. de Gier and W. E. Blumberg High resolution NMR spectroQcopy in liquids and solids - - 5 T. Axenrod Basic principles of deuterium and phosphorus-31-magnetic resonance 27 J. Seelig Use of electron spin resonance to study complex biological membranes . . ---. ---------. -. - 39 H. M. Swartz Freeze-etching electron microscopy: recent developments and application to the study of biological membranes and their components. - - . - - . - - - - . - - -- 55 T. Gu1ik-Krzywicki The nature of intramembraneous particles - - - - - - - -. 73 A. J. Verk1eij Lateral and polymorphic phase transitions in relation to the barrier function of a lipid membrane. - - - . - 81 J. de Gier C. J. A. van Echte1d J. A.