This paper describes a new type of ELISA plate in which the reaction wells have been coated with silica gel. ELISA using these prototype silica-ELISA plates is markedly more sensitive for glycolipid antigens in lipid mixtures than ELISA using polystyrene plates without silica. Silica-ELISA plates also improve the analysis of certain protein and carbohydrate antigens. This technology may be of considerable benefit in the analysis of minor lipids and other antigens from human brain, cerebrospinal fluid or blood.