Hello, I am trying to replicate the knockout of the cytoplasmic catalase production gene CTT1 as done in this paper: Article Improving carotenoids production in yeast via adaptive labor...

I use the same primers for homology to the genome, but instead of using the NEO gene I amplify the KanR selection gene from the yeast toolkit (pYTK077): Article A Highly Characterized Yeast Toolkit for Modular, Multipart Assembly

I have tried selection of both 200mg/L and 500mg/L G418 YPD agar plates, in both cases a lawn grows, and colony PCR shows that the CTT1 gene remains perfectly intact with no G418.

If you have any experience with this sort of problem I would be grateful for any help/solutions/advice.