For some years now, RNAi has been the workhorse of genomic screening projects. While the plenty of investigators have slogged through experiments and data using RNAi—with an array of useful data resulting—newly developed genome editing technology is poised to provide faster and cheaper solutions for a better understanding of gene function and smarter identification of drug targets for complex diseases.
Now, Synthego, a genome engineering solutions provider have just launched modified synthetic single guide RNA (sgRNA) libraries for arrayed whole human genome CRISPR screening. These newly developed libraries provide comprehensive coverage of the human genome, with several guide RNAs selected per gene, using the latest algorithms to enhance knockout efficiency—leading to increased screening capabilities over RNAi and CRISPR pooled libraries.
“Arrayed functional screening with high quality modified synthetic sgRNA libraries simplifies development and enables scientists to rapidly screen in an unbiased manner for relevant phenotypes in any cell type, including human stem cells and primary cells,” explained Abhi Saharia, Ph.D., director of product management. “This paves the way for the advancement of drug discovery and medical applications through faster and more accurate identification of new drug targets and a better understanding of the gene function.”
While pooled lentiviral CRISPR screening addresses some RNAi challenges, it's not ideal as it introduces large numbers of guides into cells, and limits assays to only a few screening phenotypes, such as cell growth and death. Pooled lentiviral screening also poses logistical challenges such as working with live virus, guide representation bias, variable editing efficiencies, and complicated data deconvolution through next-generation sequencing (NGS).
The new libraries can replace RNAi and pooled CRISPR screening by combining the advantages of an arrayed format, high-quality target designs, modified synthetic sgRNA, and whole genome coverage. The arrayed sgRNA libraries are designed to be ready-to-transfect into any human cell type and enable straightforward testing, assaying and analysis of complex phenotypes beyond cell viability. This methodology allows for identification of targets involved in complex disorders such as neurodegeneration and cardiovascular disease.
Utilizing the modified sgRNA during the screening phase, researchers can translate their results directly to the next phases of development without any need to change guide formats. Furthermore, arrayed screening with modified synthetic sgRNA eliminates aforementioned logistical challenges with an automation-friendly, virus-free, transfection-ready sgRNA library that provides consistent editing efficiencies without complicated NGS.
The new whole human genome library is available in gene families including the druggable genome, transcription factors, G-protein coupled receptors, kinases, and immunology and immuno-oncology targets, among others. This important feature enables focused CRISPR screens, allowing hypothesis-driven gene targeting and running of simultaneous screens without overlap.