AUTOMATIC AND SIMULTANEOUS ANALYSIS OF LENS-CULINARIS AGGLUTININ-REACTIVE ALPHA-FETOPROTEIN RATIO AND TOTAL ALPHA-FETOPROTEIN CONCENTRATION

An automated analytical method for analyzing alpha-fetoprotein (AFP) c arbohydrate chain microheterogeneity based on competitive reaction bet ween lectin and anti-AFP monoclonal antibody in liquid phase is descri bed. The antibody used binds to all species of AFP molecule without Le ns culinaris agglutinin (LCA); however, its binding reaction to LCA-re active AFP was inhibited by LCA. Sulfated tyrosine octamer was conjuga ted to the antibody, and sulfated tyrosine pentamer and peroxidase wer e conjugated to other monoclonal antibodies, respectively. Serum react ed with three anti-AFP monoclonal antibodies and LCA in liquid phases, and two types of immune complex were observed. The two types were sep arated directly by the liquid-phase binding assay system equipped with an anion-exchange column. Peroxidase activity of immune complex was d etermined fluorophotometrically. Total AFP concentration and the ratio of LCA-reactive AFP in samples were calculated simultaneously, using the sum of the two peaks and the ratio of peaks obtained by LCA inhibi tion to sum of two peaks. The results correlated well with conventiona l methods. The method is simple and convenient for routine clinical as says.