We are excited to have just completed the launch of the 3rd Module of the DECIPHER Project Human Lentiviral RNAi Library. As many of you may know, the DECIPHER Project is an open access platform that provides researchers from academic and non-profit institutions with free pooled shRNA libraries and software for genome-wide RNAi screening. It was established by Cellecta, Inc. in October 2010 under collaboration and joint grants with the Fred Hutchinson Cancer Research Center, the Roswell Park Cancer Institute, and The Scripps Research Institute.
The addition of the 3rd DECIPHER Human shRNA Expression Library Module to the DECIPHER pooled shRNA library collection adds approximately 5,000 new cell surface, extracellular, and DNA binding target genes to the 10,000 well-annotated signal transduction and disease-associated genes targeted by the other two Human shRNA expression library modules that have been available since last October. Combined, all three human modules enable functional screening of over 15,000 expressed transcripts—the majority of annotated human genes. This puts us significantly closer to our goal of providing 5 modules that target the entire genome.
The DECIPHER Project libraries are made to the same standards as all Cellecta libraries. Each individual library module targets approximately 5,000 well-annotated genes with 27,500 shRNAs (~ 5-6 shRNA target each transcript). The shRNA template oligonucleotides used to make the libraries are produced using Agilent’s array-based oligo synthesis platform which ensures relatively even representation of each oligo since each is synthesized on its own “spot” in situ on a glass surface. In addition, each shRNA insert in each of the libraries includes a unique bar-code identifier that enables its accurate identification by HT sequencing. This allows precise quantification of all shRNA species in the library and reliable measurement of shRNA quantities after screening. We essentially measure the frequency of each of the 27,500 shRNA sequences in the library. As a result, we know if any are missing after the cloning and packaging steps, and that greater than 95% of the shRNA sequences in each of our pooled shRNA libraries are present at sufficient levels to ensure statistically accurate results.