(a) Schematic of Perturb-seq strategy to capture single-cell transcriptomes with matched sgRNA identities. (b) Summary of sequencing and perturbation assignment statistics. (c) Distribution of number of cells captured per perturbation. Median: 122 cells per perturbation; 5th to 95th percentile: 66 – 277 cells per perturbation. n = 19,587 cells. (d, e) Comparison of (d) growth phenotypes (γ) and (e) relative activities measured in the large-scale mismatched sgRNA screen and in the Perturb-seq experiment. Differences are likely due to the different timescales and the different vectors used. n = 128 sgRNAs; r2 = squared Pearson correlation coefficient.