A monoclonal antibody which differentiates between bound and free human secretory component

In this study a mouse monoclonal antibody ( LICR -LON- LC28 ) to human secretory component (SC) is reported. This antibody binds to free SC or to SC associated with IgA or IgM. It exhibits a 10-fold higher affinity for SC bound to IgA than for free SC. The affinity of the antibody for SC associated with IgM is equivalent to that seen for free SC. LICR -LON- LC28 appears to be species specific and does not cross-react with other human milk proteins.