Saturated synthetic lecithins in VDRL and Kolmer antigens for the sero-diagnosis of syphilis.

When pure individual synthetic lecithins became available for study (Baer and Kates, 1949, 1950), there was immediate interest in their possible use in cardiolipin antigens as substitutes for Pangborn lecithin. Rosenberg (1949) reported briefly on synthetic L-c-(dipalmitoyl)-lecithin in antigens for the Hinton, Kline, Rein-Bossack, VDRL, and Kolmer tests. He found that replacement of Pangborn's lecithin by identical amounts of synthetic lecithin gave antigens which were reactive. Kline (1950) found that L-cx-(dimyristoyl)-lecithin gave reactive antigens, and Allen and Tonks (in a publication by Baer, Martin, Allen, and Tonks, 1951) reported that this compound and its optical isomer, Do-(dimyristoyl)-lecithin, when used in the same concentrations, gave VDRL antigens of similar reactivities. Faure and Marechal (1952) found that the synthetic lecithins were unstable and concluded that they were not suitable for antigens for the Kline, Debains, and Kolmer tests. However, improved procedures for the preparation and purification of the lecithins (Baer and Maurukas, 1952; Baer, 1953) resulted in more stable, crystalline materials. After extensive studies with crystalline L-oc-(dimyristoyl)-lecithin, Kline (1954 a, b, 1955) reported favourably on its use in antigens for his flocculation test. Reyn, Bentzon, and Hartmann (1956) studied one batch of crystalline L-oa(dimyristoyl)-lecithin in complement-fixation and VDRL antigens, and concluded that further investigations with other batches of the lecithin were warranted. Reyn and Bentzon (1956) showed that