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

Background: Immunohistochemistry (IHC) is a practical technique that utilizes the specific binding between an antigen and antibody to detect and localize specific anti-gens in tissue and cells. The optimal sensitivity in IHC is of utmost importance to achieve reliable results even when antigens are present at low abundance on the sam-ples. Here, a dextran polymer labeled with Horseradish Peroxidase (HRP) and an anti-body to improve the sensitivity of the IHC technique was synthesized. Methods: To this end, free thiol groups were introduced on sodium periodate-activated 30 kDa dextran using cystamine, followed by attachment of sulfo-MBS-activated goat anti-mouse antibody and sulfo-MBS-activated HRP to the activated dextran. Results: The production of Poly-HRP Antibody (PHA) was confirmed by the appear-ance of a new protein band exceeding 150 kDa on Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). Additionally, Enzyme-Linked Im-munosorbent Assay (ELISA) and IHC techniques were employed to characterize PHA’s functionality. The data demonstrated that PHA effectively detected target antigens in these assays. Conclusion: The newly synthesized PHA has the potential to provide a more sensitive platform for early detection of biomarkers in IHC. Further research is needed to evalu-ate its cost-effectiveness.