Impact of X-Ray Versus Gamma Irradiation of Single-Use System Filter Assemblies on CHO Cell Culture Growth

While gamma irradiation is commonly used as a standard for sterilization of single-use systems (SUS) in the biotech industry, an alternative sterilization mode using X-ray irradiation has been introduced. The integrity, safety, and performance of X-ray-treated SUS must be confirmed prior to implementation. This investigation employs gamma- and X-ray-treated SUS, comprised of filters, tubing, and bags, to sterilize media at filter loadings of 4, 20, and 100 L/m 2 to evaluate the impact of potential extractables and leachables (E&L) on viable cell density and viability of Chinese hamster ovary cells. Statistical results confirm equivalent cell growth using media sterilized by X-ray and gamma-irradiated SUS, even at the worst-case filter loading. As the industry evolves toward acceptance of X-ray sterilization, this approach supports X-ray as a viable irradiation option and, further, provides a standard for future evaluation of the impact of E&L from SUS treatment on cell performance.