plants, algae and fungi, and the identification of the many unusual sterols from marine organisms have proceeded in parallel and somewhat independently. Although the motiva­ tion and goals for the various lines of investigation have differed widely the researchers working in each of these areas have contributed a wealth of knowledge to the literature relating to the analysis of sterols and many diverse new sterols have been discovered. We conceived this book as a modest attempt to bring together some of this literature in the hope that it may be helpful to newcomers to sterol research. We had originally intended to produce a 'handbook' outlining in detail the protocols to be followed for sterol extraction, chromatography, NMR analysis, etc. in order to identify the components of a sterol mixture.