Quantitative study of enzyme immunocytochemical reactions performed with enzyme conjugates immobilized on nitrocellulose.

The nitrocellulose binding assay was used for quantitative studies on the cytochemical reactions for the three enzymes most frequently used in immunocytochemistry. The results show a linear relationship between the amount of enzyme immobilized on nitrocellulose and the amount of the enzyme reaction product. The similar course of the formation of the reaction product after DAB/H2O2 staining for peroxidase immobilized on nitrocellulose and for immunoperoxidase labeled cells indicates a linear relationship between the amount of enzyme-coupled antibodies bound to cells and the amount of enzyme reaction product. Furthermore, a mild acid treatment for the abolition of endogeneous peroxidase activity in tissues and cells applicable to immunoperoxidase staining procedures is proposed.