Serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) are standard tools for multiple myeloma (MM) routine diagnostics. M-protein is a biomarker for MM that can be quantified with SPE and characterized with IFE. We have investigated combining SPE/IFE with targeted mass spectrometry (MS) to detect and quantify the M-protein. SPE-MS assay offers the possibility to detect M-protein with higher sensitivity than SPE/IFE, which could lead to better analysis of minimal residual disease in clinical laboratories. In addition, analysis of archived SPE gels could be used for retrospective MM studies. We have investigated two different approaches of measuring M-protein and therapeutic monoclonal antibodies (t-mAbs) from SPE/IFE gels. After extracting proteotypic peptides from the gel, they can be quantified using stable isotope labeled (SIL) peptides and measured by Orbitrap mass spectrometry. Alternatively, extracted peptides can be labeled with tandem mass tags (TMT). Both approaches are not hampered by the presence of t-mAbs. Using SIL peptides, limit of detection of the M-protein is approximately 100-fold better than with routine SPE/IFE. Using TMT labeling, M-protein can be compared in different samples from the same patient. We have successfully measured M-protein proteotypic peptides extracted from the SPE/IFE gels utilizing SIL peptides and TMT.

中文翻译：

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将血清蛋白电泳与质谱相结合，这是用于M蛋白检测和定量的新工作流程。

血清蛋白电泳（SPE）和免疫固定电泳（IFE）是多发性骨髓瘤（MM）常规诊断的标准工具。M蛋白是MM的生物标志物，可以用SPE定量并用IFE表征。我们已经研究了结合使用SPE / IFE和靶向质谱（MS）来检测和定量M蛋白。与SPE / IFE相比，SPE-MS分析提供了以更高的灵敏度检测M蛋白的可能性，这可能导致对临床实验室中的最小残留疾病进行更好的分析。此外，对存档的SPE凝胶的分析可用于回顾性MM研究。我们研究了从SPE / IFE凝胶中测量M蛋白和治疗性单克隆抗体（t-mAb）的两种不同方法。从凝胶中提取蛋白型肽后，可以使用稳定的同位素标记（SIL）肽对它们进行定量，并通过Orbitrap质谱法进行测量。或者，可以用串联质量标签（TMT）标记提取的肽。t-mAb的存在并不妨碍这两种方法。使用SIL肽，M蛋白的检出限比常规SPE / IFE高约100倍。使用TMT标记，可以比较同一患者不同样品中的M蛋白。我们已经成功测量了利用SIL肽和TMT从SPE / IFE凝胶中提取的M蛋白蛋白型肽。M蛋白的检出限比常规SPE / IFE高约100倍。使用TMT标记，可以比较同一患者不同样品中的M蛋白。我们已经成功地测量了利用SIL肽和TMT从SPE / IFE凝胶中提取的M蛋白蛋白型肽。M蛋白的检出限比常规SPE / IFE高约100倍。使用TMT标记，可以比较同一患者不同样品中的M蛋白。我们已经成功测量了利用SIL肽和TMT从SPE / IFE凝胶中提取的M蛋白蛋白型肽。