Fetal bovine serum (FBS) was — and in many cases still is — the supplement of choice to maintain the viability of mammalian cells in culture. However, there are considerable limitations to its use. In the early days of cell culture, the issues surrounding serum were mainly its variable performance and the potential to contaminate cultures with fungi, viruses, and bacteria. Early attempts to produce a serum-free medium (SFM) were academic exercises that usually relied on the use…
Biochemicals/Raw Materials
A Readily Available Source of BSA Consistently Supports Cultivation and Differential Gene Expression
Lyme disease caused by the spirochete Borrelia burgdorferi is the leading vector-borne illness in the United States (1). The natural infectious lifecycle of B. burgdorferi is complex in that it is necessary for the bacteria to colonize both an arthropod vector (the Ixodes scapularis tick, pictured right) and a mammalian host (2). As the bacteria transitions between those two diverse niches, it alters the expression of its major outer surface proteins (Osps) such that expression of those that…
Determining the Effect of Raw Materials on Manufacturing-Scale Cell-Culture Performance
Large-scale cell culture production processes routinely involve multicomponent cell culture media formulations including both chemically defined raw materials and complex raw materials such as hydrolysates (1). Even minor variations in the compositions of either can lead to variability in protein productivity or product quality. That often persists despite the use of a raw material lot-blending strategy at large scales to “average out” raw material trends. And a raw material lot-blending strategy can makes it more difficult to identify which single…