Immunoglobulin M(IgM) Determination Reagent(Immunoturbidimetry) is an in vitro diagnostic quantitative test kit. This test is used to establish the diagnosis and monitor therapy in macroglobulinemia of Waldenström or plasma cell myeloma. IgM levels are used to evaluate likelihood of in utero infections or acuteness of infection. Immunoglobulin M is a pentamer of 7S γ-globulin and is an efficient complement binder. It is the antibody type produced initially in the immune response and the first immunoglobulin class to be synthesized by a fetus or newborn. IgM antibodies do not cross the placenta. For these reasons the demonstration of IgM-specific antibody is useful in assessing whether a particular infection is acute or chronic.