Pooled sgRNA libraries vs. pooled RNAi libraries vs. targeted arrayed sgRNA libraries
Pooled sgRNA libraries vs. pooled RNAi libraries vs. targeted arrayed sgRNA libraries
sgRNA vs. RNAi libraries
Unlike RNAi libraries, sgRNA libraries produce a complete knockout (vs. a knockdown) phenotype and have a reduced likelihood of off-target effects. Genes that play a vital role in causing your phenotype of interest but still cause the phenotype at low expression levels may only be detected following the complete knockout resulting from a CRISPR/Cas9 screen.
Pooled vs. targeted arrayed libraries
Arrayed libraries are beneficial if you wish to screen only a known subset of genes for a phenotype or are seeking to assay phenotypes that don’t result in enrichment or depletion; however, these often require automated liquid-handling capabilities, and you almost always need to know what you are looking for. Pooled sgRNA libraries are used more for discovery and allow for an unbiased approach; it is easy to screen the whole genome using a pooled library, and automated liquid handling is not required. The cost of an arrayed targeted library increases with the number of genes assayed.