Has there been any impact on karyotype of the cells with the recombinant versions of the proteins?

Answer

We routinely look at cellular phenotype via expression of phenotypic markers specific for the cell type of interest as well as cellular function and differentiation (if relevant). We have found that, in terms of phenotype and growth kinetics, that cells cultured in the presence of these recombinant proteins are normal and display the expected growth kinetics. Further, in specific applications, we find that cellular function is actually better in blood-free media versus human serum component-containing media through the deletion of bioactive serum-derived contaminates. Though karyotype is an interesting, we currently have not looked at this quality parameter.