Synthesis of a Unique Dextran Polymer-Conjugated Antibody and Horseradish Peroxidase Complex

Immunohistochemistry (IHC) is a practical technique that utilizes the specific binding between an antigen and antibody to detect and localize specific antigens in tissue and cells. The optimum sensitivity in IHC is of the greatest importance to achieve reliable results even though low number of available antigens on the samples. Here, we have synthesized a dextran polymer labeled with horseradish peroxidase (HRP) and an antibody to improve the sensitivity of the IHC technique. To this end, free thiol groups were introduced on the sodium periodate-activated dextran using cystamine, and then sulfo-MBS-activated goat anti-mouse antibody was attached to the activated dextran. The production of Poly-HRP Antibody (PHA) was confirmed by the presence of a new protein band with a molecular weight of more than 150 kDa in SDS-PAGE. Additionally, Enzyme-Linked Immunosorbent Assay (ELISA) and IHC techniques were applied to characterize the PHA function. The newly synthesized PHA might bring a more sensitive and cost-benefit platform for early detection of biomarkers in IHC.