SUMMARY, EXPLANATION AND LIMITATIONS:
IgM antibody reacts with heavy chain (µ-chain) from the human immunoglobulin IgM. On cryostatic tissue this antibody marks IgM immunoglobulins contained in plasma cells, follicular B cells and dendritic reticular cells. The common feature in plasmacytomas, some leukemias and some B cells lymphomas is the expression of one unique heavy and light chain, therefore, IgM antibody is useful to mark them. On paraffin-embedded tissues, cytoplasm immunoglobulins are stained, for example in myeloma, plasmacytoma and normal plasma cells. Generally membrane bond immunoglobulins, connective tissue or blood vessels bond extracellular immunoglobulinss and immunocomplex can only be shown on frozen tissues. Plasma cells may not be much stained on frozen tissues because immunoglobulins distribute diffusely by their cytoplasm.
Immunogen: IgM isolated from human serum of a patient with Waldenstorm’s macroglobulinaemia
Staining pattern: Cytoplasmic.
Positive control: Tissue sample from tonsil.
This antibody is designed for the specific localization of human IgM using IHC techniques in formalin-fixed, paraffin-embedded tissue sections.
IgM antibody is appropriate for diagnosing B type malignant lymphoid proliferations.