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Growth Factors


Repligen cell culture supplements provide the benefits of serum supplementation while maintaining an animal-free process.

Optimizing cell culture growth and productivity is the primary goal in cell culture expansion.

Serum has historically been the most common additive to cell culture media.  It adds essential components, such as hormones and growth factors.  However, its undefined animal origin poses significant contamination risk with adventitious agents. 

While serum-free formulations are chemically-defined, they show increased oxidative stress and cell death. Growth factors can alleviate that stress and are critical for long-term growth and proliferation of many cell lines in serum-free media formulations.

Common cell growth factors

Recombinant proteins, manufactured exclusively for cell culture applications, have been shown to boost the productivity of a chemically-defined medium.The formulations are well-defined and they are manufactured following strict GMP quality conditions with a secure supply chain.  Two common cell growth factors are:


Insulin supports the serum-free growth of many cell types.  The low potency of insulin has been attributed to signaling through the IGF-I receptor instead of its own receptor. The activation of the IGF-I receptor has been shown to mediate potent proliferation and  anti-apoptotic pathways.


A more potent growth factor, such as LONG®R3 IGF-I, targets and activates the IGF-I receptor with greater specificity. The more effective activation of the IGF-I receptor by LONG®R3 IGF-I allows for significantly less protein supplementation and, therefore, less potential impact on downstream processing.

LONG®R3 IGF-I Cell Culture Supplement

LONG®R3 IGF-I Cell Culture Supplement

LONG®R3 IGF-I (LONG R3) is a recombinant analog of human insulin-like growth factor-I (IGF-I) that has been specifically engineered for the enhancement of cell culture performance.  It is 200 times more potent and two times more stable in cell culture than insulin.

long®R3 IGF-I

LONG® EGF Cell Culture Supplement

LONG® EGF Cell Culture Supplement

LONG® EGF is a recombinant analog of human epidermal growth factor (EGF) used in regulatory approved cell-based therapies. Developed as a supplement for use in therapeutic cell culture applications as a like-for-like replacement for native EGF or recombinant human EGF (hEGF). 

long® EGF