Screening	Technology	Description	Advantages and disadvantages	Ref.
Proteomics	Procode	Barcoding system that leverages the use of protein tags to enable the multiplexing of >100 unique samples Can be applied to CRISPR screens with the use of high-dimensional methods, such as CyTOF, to characterize knockout constructs en masse	Can also be used to evaluate overexpression cDNA constructs	144
Transcriptomics	Perturb-seq	Pooled single guide RNA libraries are transduced in cells of choice and used in conjunction with scRNA-seq	Combines scRNA-seq and CRISPR-based perturbations to perform many assays in a pool Limited by reliance on indirect indexing of single guide RNAs	158
	Direct capture Perturb-seq	Expression from single guide RNAs is sequenced alongside transcriptomic measurements	Targets individual genes with multiple single guide RNAs per cell; allows scRNA-seq experiments	159
	Mosaic single-cell analysis by indexed CRISPR sequencing (Mosaic-seq)	Uses a CRISPR barcoding system in combination with the measurement of single cell gene expression to readout both the phenotypic perturbations and the barcode of the specific single guide RNA	High-throughput endogenous interrogation of enhancers evaluated in single cells	160
	CRISPR droplet sequencing (CROP-seq)	A guide RNA serves as the barcode	Enables pooled CRISPR screens with single-cell transcriptome resolution Overcomes the problem of lentiviral template switching by using CROP-seq lentiviral constructs	161
Chromatin status	Perturb-ATAC	Combines CRISPR screening with scATAC-seq to measure the effect of CRISPR perturbations on chromatin status in single cells	NR	162

CROP-seq, CRISPR droplet sequencing; CyTOF, cytometry by time of flight; NR, not reported; scATAC-seq, single-cell assay for transposase-accessible chromatin using sequencing; scRNA-seq, single-cell RNA sequencing.