Immunoassay Using a Metal-complex Compound as a Chemiluminescent Catalyst. II. An Improvement of the Analytical Method for Practical Use

Immunoassay using a synthesized metal-complex compound as a labeling reagent has been investigated. Iron(III) 2,9,16,23-tetrakis(chlorocarbonyl)phthalocyanine, which showed a marked catalytic action in the chemiluminescence reaction between luminol and H2O2, was synthesized, and albumin was labeled with it. Albumin in the range from 50 ng/tube to 50 μg/tube could be determined by measuring the chemiluminescence intensity in a competitive immunoassay using glass beads immobilized with an antibody. The present method became about 40 time as sensitive as the previous method by optimizing the labeling procedure, the chemiluminescence reaction, and the immune reaction.