u/dawgmad

I'm planning an experiment to insert a T2A-eGFP fragment slightly upstream of a stop promoter in a cell line (based on the method in DOI: 10.1016/j.stemcr.2024.03.005). Basically, I have to insert the T2A-eGFP fragment between two homology arms immediately flanking the stop codon in the gene of interest, insert that construct into the cells of interest, and cut immediately upstream the stop codon using Cas9. My question - how do I decide how long to make the homology arms?

Edit - i misspelled HDR in the title sorry!