Immunophenotyping of myeloma cells with immunoalkaline phosphatase technique.

: An immunoalkaline phosphatase (IAP) technique was used to determine the class of cytoplasmic immunoglobulin presenting in the malignant plasma cells of patients with multiple myeloma. Using monoclonal antibodies against different human immunoglobulins (Igs) as the primary antibodies, and calf intestinal phosphatase as the enzymatic indicator. The presence of monoclonal immunoglobulin was demonstrated within the cytoplasm of malignant plasma cells. These results correlate well with the electrophoretic patterns of the Igs present in the serum samples of these patients. This IAP technique is suggested as a practical method for evaluating the immunophenotype of multiple myeloma.