Immunochemical properties of phosphatidyl cholesterol and its homologue.

1,2-Dipalmitoyl-rac-glycerol-3-phosphoryl-3'-cholesterol (PCH) and 1,2-dipalmitoyl-rac-glycerol-3-phosphoryl-20'-(3-hydroxy norpregn-5-ene) (PET) were combined with poly-L-lysine to form a PCH-poly-L-lysine complex and a PET-poly-L-lysine complex, respectively. These complexes were subcutaneously injected into rabbit foot pad with Freund's complete adjuvant. PCH antiserum showed specificites against the phosphatidyl group, the cholesterol moiety and the side chain of cholesterol. PET antiserum contained the specific antibodies against the phosphatidyl group, the cholesterol moiety and the OH-group at the C3 position of the cholesterol molecule.