GIPZ library plasmid/viral pool production and target cell line infection. (a) Scatter plots showing pair-wise comparisons of log2 normalized read counts from shRNA plasmid, virus and two technical replicates of shRNA constructs amplified from genomic DNA 3 days post-infection of MCF7 and HeLa cells. Numbers indicate Pearson correlation between conditions. Technical replicates show high correlation. Plasmid shows high correlation with infected cells in both cell lines. Virus shows weaker correlation with both plasmid and infected cells. (b) Test infection of a panel of breast cancer cell lines. Most cell lines show >60% green fluorescent protein (GFP)-positive cells 3 days after infection. Those that did not were puromycin selected to increase the population of GFP-positive cells to >90%. (c) Fluorescence-activated cell sorting (FACS) profiles showing the percentage of GFP-positive cells before and after puromycin selection in A549 cells.