On January 9, 2026, the U.S. Food and Drug Administration (FDA) accepted Device Master File (DMF) number MF 32345. It describes the first specific quality control protocol for mesenchymal stromal cells (MSCs), the “Tasly 3P Characterization of MSCs Assay.” This provides the first FDA-recognized standard, intended to enable consistent, safe, and effective clinical applications of MSCs.
Mesenchymal stromal cells were long mistakenly classified as stem cells. Due to a lack of uniform quality standards, they have shown highly variable clinical results in the past. The 3P assay evaluates three core characteristics: Property (cell identity), Purity (freedom from contaminants), and Potency (functional activity). This precisely characterizes therapeutic MSC products, excludes heterogeneous cell populations, and ensures biological potency.
The new standard mitigates historical risks such as tumor formation and therapeutic unreliability. It allows physicians and patients to perform a quality check before treatment. As the first FDA-approved protocol of its kind, it sets a new benchmark and accelerates the transition in regenerative medicine from a stem cell-centered to a stromal cell-focused approach.
The FDA approval aligns with the current scientific understanding that MSCs primarily act through paracrine signaling rather than differentiation. It closes a regulatory gap, complies with updated guidelines from the International Society for Cell & Gene Therapy, and is intended to facilitate Investigational New Drug applications, make clinical trials more reliable, and promote global harmonization in the evaluation of MSC products.
