An issue that should be of interest to most cell culturists is the heat inactivation of serum products. It would be inconceivable to purchase thousands of dollars worth of expensive growth factors, vitamins, amino acids, etc., and needlessly expose them to temperatures exceeding 56°C for at least 30 minutes. Nevertheless, this is exactly what takes place in many cell culture laboratories. Many cell culturists routinely heat inactivate serum products without considering how this extreme treatment affects growth factors, vitamins, amino acids, etc. One of the most frequent inquiries that we receive on our Technical Hotline is whether to heat inactivate serum. To address this concern and further bring cell culture from an art to a science, we investigated the effects of heat inactivation on fetal bovine serum (FBS).

According to some estimates, at least 70 percent of all customers who heat inactivate serum do so simply because it is included in their protocols or it has always been accepted as necessary. Recommended temperatures in the protocols range from 45°C to 62°C and times range from 15 minutes to 60 minutes. The most common procedure involves subjecting the serum to 56°C for 30 minutes. Many of these protocols originated before the 1970’s and have not been questioned. As a result of improvements in the collection, processing, and understanding of serum, many of the original reasons for heat inactivating serum are no longer valid. Only a small percentage of customers that heat inactivate their serum have actually performed experiments to verify the efficacy of the process and determined whether heat inactivation is indeed necessary.