Rat and mouse monoclonal antibodies are often used for multiple analysis, i.e., to detect proteins that are located closely. If the monoclonal antibodies are not labeled, secondary antibodies are required for distinguish rat or mouse monoclonals. However, secondary polyclonal antibodies from rabbits, goats or sheep often cross-react to rat and mouse IgG, which causes high background staining and leads misinterpreting results.

To solve this problem, we have recently developed mouse anti-rat IgG monoclonal antibodies. They can be used as secondary antibodies after labeling. They have no cross-reactivity to mouse IgG.