One-step IHC Polymer-based detection kits
Detection kits for immunohistochemistry (IHC) based on the polymers method are more recent than traditional kits using avidin and biotin conjugates such as ABC kits. Polymer-based kits offer several advantages over ABC kits, especially for multi-staining (multiplex) applications on the same tissue section or where high levels of endogenous biotin may be a problem.
The IHC detection systems based on the polymers method consist of a polymer of an active enzyme linked to a secondary antibody specific for a target primary antibody. This format makes it possible to significantly increase the amount of enzyme present at the site of localization and therefore a greater signal by converting a greater quantity of substrate into precipitate. Moreover, this system allows a one-step protocol instead of two with the ABC system (biotinylated antibody + avidin-enzyme complex).
The polymers may be based on dextran or similar molecules which have a large size (causing problems in some tissues) or micro-polymers that penetrate more easily into the tissue sections.