A simplified purification of lecithin.

A practical and easily reproducible method for preparing lecithin of a high degree of purity is urgently needed in connection with the use of lecithin in cardiolipin antigens (1, 2). Methods devised for this purpose have been published (3, 4), but the procedures, based on the classic studies of Levene and his coworkers (5, 6), were somewhat tedious and the lecithins so prepared have not always been satisfactory. Continued effort has therefore been devoted to simplifying and improving the available methods. The procedure here described has been adopted after numerous experiments in which many combinations of solvents were tried. The details are presented by describing a typical preparation of egg lecithin. The purification of lecithin occurring in such complex mixtures as tissue extracts is more difficult, and each source material can be expected to present special problems. An example is beef heart, which was actually used for most of the experiments by which the present method was developed, and the modifications found necessary for this particular case are discussed. Since egg lecithin can be purified so much more easily, it is hoped that this product can be universally substituted for beef heart lecithin in cardiolipin antigens. Comparative studies of the two lecithins from this point of view will be reported elsewhere.