Figure 1

A: BAC hybridisation of relevant region to the large and small chromosome 8. Only the small chromosome 8 contains the region of interest. B: Comparison of G418 batch and MTX fed-batch titers expressed in the three new CHO cell lines in comparison to CHO-K1 cells. A massive increase of pool productivity could be detected. C: A variety of assays were applied to identify the key protease. These include broad spectrum protease inhibitors, mass spectrum analysis, next generation sequencing and siRNAs. D: Evaluating proteolytic degradation in conditioned medium between WT cell line and protease KO cell line