The split-GFP, and splitHalo landing pad HEK293Ts, were generated from a published landing pad parent cell line 28 (link) seeded at 100k cells in a 12-well plate. To each well, 600 ng of BxbI Integrase Expression Vector (Addgene #51271) and 600 ng of each landing pad donor plasmid were co-transfected. Once cells are confluent, cells were split once and seeded in a T25 flask, and blasticidin (Gemini Bio-Products 400-165P) was added at 5 μg/mL for selection prior to FACS sorting integrated cell lines.