Use of an individual unsaturated lecithin from yeast in antigens for the sero-diagnosis of syphilis.

Hanahan and Jayko (1952) isolated a pure individual unsaturated lecithin, L-ox-(dipalmitoleyI)lecithin, from fresh baker's yeast by adsorption on alumina. They showed that hydrogenation of this material produced the corresponding saturated lecithin which was identical with the synthetic L-oc-(dipalmitoyl)-lecithin of Baer and Maurukas (1952). The latter compound, when used in combination with cardiolipin and cholesterol, has given antigens suitable for the sero-diagnosis of syphilis (Tonks and Allen, 1953). Samples of Hanahan's lecithins were obtained and tested in antigens prepared for the Kolmer complement-fixation test and the VDRL microflocculation test. Antigens containing the unsaturated lecithin proved to be reactive in both tests. Since this pure material is quite stable, as determined by chemical tests, is relatively easy to prepare, and is a solid which can be measured by weighing, it offers promise for use as the lecithin component of cardiolipin antigens. Antigens containing the saturated material showed very little reactivity in the VDRL test when used at a concentration found previously by Tonks and Allen (1953) to be optimal for Baer's synthetic saturated lecithins. However, in the Kolmer test, Hanahan's preparation gave results almost identical to those obtained with Baer's material.