Can the COA report of fetal bovine serum be used for preclinical cell experiments without virus detection results?

Low price and short lead times cannot replace a complete quality package. When selecting domestic serum for preclinical immune cell expansion, I generally require suppliers to provide: COA, irradiation certificate, viral and mycoplasma testing reports (preferably third-party), TSE/BSE statements, production process and quality system certifications. Without these, no matter how low the price, it is not recommended for direct use in critical experiments. It can be specified in the procurement contract that if missing test items lead to experimental failure or document rejection, the supplier shall be responsible for returns, exchanges, and corresponding losses. First, have the supplier send a small sample along with a full set of testing reports.

For human immune cell expansion, followed by preclinical safety evaluation, a COA lacking viral and mycoplasma testing is clearly insufficient. Preclinical safety evaluation typically requires that serum undergo at least gamma irradiation or filtration sterilization, along with viral and mycoplasma testing reports. If the supplier has not provided these, it is advisable to request supplementary third-party testing or irradiation certification. Otherwise, this may be questioned during subsequent ethics or regulatory review. Paying extra for testing is more cost-effective than having the experiment invalidated.

If the lead time is only 3 days but the COA is incomplete, you can consider sending samples to a third-party lab for mycoplasma and virus testing yourself, but virus testing typically takes several days to several weeks and may affect your timeline. It is advisable to prepare on two fronts simultaneously: on one hand, ask the supplier to complete the testing as soon as possible or provide historical batch reports; on the other hand, look for an alternative supplier with a complete COA. About 1,200 yuan for 500 mL is indeed not expensive, but if inadequate validation leads to failure of the entire immune cell expansion batch, the cost would far exceed the price difference in serum. If time permits, first perform small-scale culture validation for sterility, mycoplasma, and cell expansion fold.