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 optimal sensitivity in IHC is of utmost importance to achieve reliable results even when antigens are present at low abundance on the samples. Here, a dextran polymer labeled with Horseradish Peroxidase (HRP) and an antibody to improve the sensitivity of the IHC technique was synthesized.

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.

The production of Poly-HRP Antibody (PHA) was confirmed by the appearance of a new protein band exceeding 150 kDa on Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). Additionally, Enzyme-Linked Immunosorbent Assay (ELISA) and IHC techniques were employed to characterize PHA's functionality. The data demonstrated that PHA effectively detected target antigens in these assays.

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 evaluate its cost-effectiveness.