Affinity chromatographic purification of immunoglobulin M antibodies utilizing immobilized mannan binding protein.

A method is described for the rapid and efficient affinity chromatographic purification of murine monoclonal immunoglobulin M (IgM) which utilizes immobilized rabbit mannan binding protein (MBP). This solid-phase matrix is shown to bind IgM-class antibodies from a variety of species. Conditions reported show a binding capacity of IgM from murine ascites of nearly 1 mg/ml of immobilized MBP support. The prepared gel is shown to possess an ability to bind not only mouse IgM, but also human and bovine IgM, although with a lesser affinity. The matrix can be regenerated and reused at least ten times without any apparent loss of binding capacity or specificity. Mouse monoclonal IgM purified from ascites fluid using this method is greater than 95% pure as shown by high-performance liquid chromatography analysis.