<p>Dynamic quantification of monoclonal immunoglobulin proteins (M-proteins) by immunotyping using immunosubtraction (ISUB) through capillary zone electrophoresis (CZE) was performed to examine the efficacy of chemotherapy drugs in patients with multiple myeloma (MM). Twenty-one patients with eight different types of M-protein were analyzed, and M-protein quantification during chemotherapy regimens was dynamically monitored. For patients with M-protein identified by CZE, immunotyping by ISUB can accurately determine the percentage of M-protein. In this study, 15 of the 16 included patients with a definite diagnosis of MM were initially treated with bortezomib chemotherapy, and the treatment efficacy differed significantly among individuals. Three patients showed M-protein clearance, with the M-protein decreasing by more than 50% after the first course of treatment. Capillary-based immunotyping accurately determined the percentage of M-proteins. Dynamic monitoring of M-protein through immunotyping using ISUB can objectively and effectively aid in evaluating treatment efficacy. Clinically, chemotherapeutic drugs that reduce M-protein levels by more than 50% after a treatment course should be selected. The early detection of trace changes in M-protein levels is crucial for disease monitoring and medication guidance. Quantification of M-protein should be regularly undertaken in patients with MM.</p>