Abstract
The studies reported were done with the objectives of preparing several different peroxidase-labeled antibody conjugates and of testing their usefulness for the detection of soluble and insoluble tissue antigens. Glutaraldehyde, toluene diisocyanate and N,N'-dicyclohexyl carbodiimide were used to cross-link horseradish peroxidase to goat anti-rabbit immunoglobulin G; the resulting conjugates were characterized by molecular size and enzymatic and immunologic activity. They were then tested for their properties as immunohistologic reagents using 0.5-µ sections of freeze-substituted paraffin-embedded renal cortical tissue. Excellent results were obtained with a highly polymerized conjugate made with glutaraldehyde and with an unpolymerized conjugate made with toluene diisocyanate. With the use of these conjugates tissue localization of both soluble and insoluble antigens was achieved after subsequent fixation of tissue and counterstaining with periodic acid-Schiff-hematoxylin.