IMMUNOASSAY USING A METAL-COMPLEX COMPOUND AS A CHEMI-LUMINESCENT CATALYST .1. IRON(III)PHTHALOCYANINE AS A LABELING REAGENT

A synthesized metal-complex compound with catalytic activity for a chemiluminescence reaction has been used for the first time as a labeling reagent for immunoassay. Several complex compounds of iron(III) and cobalt(II) were synthesized, and their catalytic activities for the chemiluminescence reaction between 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol) and hydrogen peroxide (H//2O//2) were examined. Iron(III) 4,11,18,25-tetracarboxyphthalocyanine (TCP-Fe(III)) showed the highest catalytic activity. The immunoassay of free albumin was carried out by a competitive method using albumin labeled with TCP-Fe(III) by means of the carbodiimide method; free albumin in the range of 2 to 1000 mu g/tube could be determined with a coefficient of variation of from 6 to 16% in 5 analyses.