The protein hydrolysate, Primatone RL, is a cost-effective multiple growth promoter of mammalian cell culture in serum-containing and serum-free media and displays anti-apoptosis properties.

The tryptic meat digest Primatone RL is a low-cost medium supplement of a complex nature which serves as a source of amino acids, oligopeptides, iron salts, some lipids and other trace low molecular weight substances. Its addition to mammalian and insect cell culture media significantly improves the cell growth properties of many cell lines. In this work the growth promoting effects of Primatone RL are described in more detail using different mouse hybridomas, a mouse myeloma cell line, and human promyelocytic leukemia HL-60 cells. The positive effects on cell growth induced by Primatone were observed in the presence of serum but were even more pronounced in serum-free culture. In addition the adaptation time from high serum to low (1%) or serum-free growth in the presence of Primatone is also significantly reduced. Primatone RL, when added to HL and DHI medium, improves cell growth under low serum or serum-free conditions by increasing the maximum cell numbers and in particular the viability of the culture. The observed decrease in cell death (apoptosis) induction leads to a significant improvement in antibody (recombinant protein) production by increasing the volumetric yields during long-term batch culture. The so-called anti-apoptotic effects of Primatone RL for mouse hybridomas, which is concentration dependent, is not fully understood.