Chapter 2 Recent Methods for the Elucidation of Lipid Structure R. A. KLEIN Medical Research Council Molteno Institute University of Cambridge Cambridge, England and P. KEMP Agricultural Research Council Institute of Animal Physiology Cambridge, England 1. INTRODUCTION The first essentially correct structure for a phosphatidylcholine was pub- lished by Strecker in 1868. Indeed the structure shown corresponds, perhaps fortuitously, to the single molecular species l-palmitoyl-2-0Ieoyl-3-sn- glyceryl-phosphorylcholine. The precise position of the two fatty acids was still under debate 90 years later (Tattrie, 1959; Hanahan et al., 1960; de Haas et al., 1960; de Haas and van Deenen, 1961). This was a truly remarkable achievement, given that Strecker possessed none of the highly sensitive or selective analytical methods currently available. 51 E. D. Korn (ed.), Methods in Membrane Biology © Plenum Press, New York 1977