DOI: 10.1373/clinchem.2008.112946


These cases remind us that IgM monoclonal proteins (M-proteins) have earned a reputation as saboteurs of many laboratory assays owing to their self-aggregation, aggregation of latex particles, binding to analytes and reagents, and cryoprecipitation. One additional point is that some IgM M-proteins also play havoc with their own detection and measurement by electrophoretic techniques.