Alves, Paula M.Hauser, HansjörgNorton, Leonor da Gama Carvalho2011-06-092011-06-092010-06http://hdl.handle.net/10362/5770Dissertation presented to obtain a Ph.D. degree in Sciences of Engineering and Technology, Cell Technology, at the Instituto de Tecnologia Química e Biológica, Universidade Nova de LisboaTechnologies enabling expression of recombinant genes in mammalian cells belong to the tools of the trade in molecular biology. These technologies can serve a wide variety of purposes, ranging from basic research to elucidate gene functions e.g., in transgenic mouse models, to biotechnological applications such as manufacturing antibodies or producing viral vectors. In cell line development, the integration of transgenes into the chromosomal DNA of the host cell is a crucial step, since chromosomal surroundings have a major impact on the expression of the transgene. With regard to safety, product consistency and operational transparency, expression of biotechnological relevant products from single copy DNA integrants is preferable over a scenario of multi‐gene integrants.(...)engdoctoral thesis