What quality inspections are required for the new batch of fetal bovine serum containing mesenchymal stem cells before storage?

For new batches of serum, you must perform parallel validation using your own umbilical cord MSCs, not just rely on the COA. Take cells from the same passage and at the same seeding density, and culture them synchronously from P2 to P4 with a historically qualified batch and the new batch. Record attachment time, morphology, confluence, cell count, and population doubling time. It is best to additionally perform colony-forming unit assays and observe stability over 3 consecutive passages. Then use flow cytometry to detect the positivity rates of CD73, CD90, and CD105, as well as negative markers such as CD34, CD45, and HLA-DR, and simultaneously perform comparative osteogenic, adipogenic, and chondrogenic differentiation. Acceptance thresholds should be pre-set based on historically qualified batches, rather than judged by a single cell count.

At the incoming material level, in addition to sterility and endotoxin, mycoplasma testing is also required, along with verification of viral safety statements, blood origin, filtration process, and total protein, hemoglobin, IgG, osmolality, and pH in the COA. MSCs are sensitive to adherence and growth factors; it is recommended to add low-density adherence/growth assays and short-term serial passaging validation; retain at least 0.5-1 mL of sample per lot at -80°C for reference. The two catalog numbers should be numbered separately, stored separately, and validated separately; do not mix them. If there is a significant decline in proliferation, cell enlargement and elongation, or spontaneous differentiation, even if the COA is qualified, it is not recommended to enter the main process; consider return/exchange or repurposing for ordinary cells.