During the transit process of engineered B cells to plasma cells, a profound metabolic alteration occurs to accommodate lineage changes to protein-secreting cells. There is not abundant knowledge on the differentiation program, and it is necessary to evaluate the engineered cell products by monitoring the metabolic state of cells during differentiation. Metabolomics allows the global characterization of metabolite parameters, such as compounds consumed and released in the differentiation process, helping to understand the complex process by identifying biomarkers and determining the metabolic pathways in a cell. Nuclear magnetic resonance spectroscopy (NMR) is an advanced, sensitive technique that can be used for metabolomics study.