The development of new mammalian expression platforms represents an ongoing need for advancing biophar-maceuticals towards human clinical trials.
In an effort to address this issue, we have developed new solutions for more efficient identification of individ-ual protein candidates in stably trans-fected CHO cells. We have shown that the combination of high transfec-tion efficiency with the presence of chromatin structural elements (Selexis Genetic Element) in the ex-pression vectors results in higher effi-ciency of expression and stability of engineered cells. This allows the pro-tein of interest to be readily secreted and recovered in high yield from the medium. Based on this approach, combinatorial human antibody librar-ies are generated in CHO cells to al-low the identification of the most promising human antibody for binding and expression.