This fatty acid methyl ester mixture contains 19 fatty acids for the identification and quantification of unknowns.1 It is prepared from high purity stock material and contains saturated and unsaturated fatty acids. This mixture is very useful for bacterial identification,2 triglyceride determination and the analysis of various plant and animal lipids.3 Understanding the role of fatty acids and fatty acid metabolism in plants and animals is important in drug development. Composition: It contains the methyl esters of the following fatty acids (mg/ml in parentheses):,C8:0 (0.3),C10:0 (0.5),C12:0 (1.0),C13:0 (0.5),C14:0 (0.5),C14:1 (0.3),C15:0 (0.3),C16:0 (2.0),C16:1 (1.0),C17:0 (0.5),C18:0 (1.0),C18:1tr (0.4),C18:1c (3.0),C18:2 (2.0),C20:0 (0.3),C18:3 (1.0),C20:1 (0.3),C22:0 (0.3),C22:1 (0.3),listed in order of their elution.