The possibility of using inorganic catalysts as markers for solid-phas
e immunoassay on the plates is shown with iron-containing hydrosols: f
errum hydroxide, ammonium ferriglycerate, and ferrum hydroxide modifie
d with potassium ferrocyanide. Diagnostic agents based on iron-contain
ing sols with dispersion of 0.5 to 0.8 mm bound to immunoglobulins or
staphylococcal protein A are no less sensitive Chan the immunoperoxida
se agents, provided the same developing system is used (o-phenylenedia
mine + hydrogen peroxide). The sensitivity of solid-phase immunocataly
tical assay of purified vaccinia and Venezuelan equine encephalomyelit
is virus antigens was about 2 and 10 ng/ml, respectively. Hence, inorg
anic catalysts are prospective markers for immunoassay.