I was just going to start an experiment with the PX458 and PX459 plasmids for the deletion of an 800bp long gene segment. These plasmids, somehow, seem to create clones with heterologous deletions in other labs working with the same plasmid. Are there any hacks/ tricks/tips that could help improve the situation and help me create a murine epithelial cell line with a homozygous deletion?

- Much thanks :)