Assay Development and Optimization: Establish optimal experimental conditions, including those for a) lentiviral transduction and b) screening parameters, such as selective pressure and time between collection of reference and experimental samples.
Primary Screen: A stable population of cells expressing single integrands of constructs are created by transducing lentiviral pools at low MOIs. Transduced cells are then split into reference and experimental populations for application of a selective pressure that induces the phenotype of interest. Genomic DNA (gDNA) is then isolated from reference and experimental populations of transduced cells. Illumina-adapted primers and Phusion Hot-Start II High Fidelity DNA Polymerase are used to PCR amplify integrated construct sequences and add Illumina flow-cell binding sequences. The resulting amplicons are run on Illumina platform sequencers, using the sequencing primers provided.
Hit Identification and Follow-up: Construct sequences are identified in reference and experimental libraries. Constructs that are enriched or depleted during the screen are identified as hits, and the genes that they target are identified. Hits can be confirmed and studied further using individual constructs that can be ordered from the Dharmacon catalog collection.
Promoter activity varies across several human and rodent cell lines. Cells were plated at a density of 50,000 cells per well in a 24-well plate and transduced at MOI = 15 with SMARTvector Empty Vector Control Particles expressing TurboGFP. Promoter activity was assessed at 72 hours post-transduction by the fluorescence intensity of TurboGFP.
The Human-Mouse Conserved microRNA pooled library is useful for researchers that need ultra-high fold coverage for subtle phenotypes, or who may not have enough cells (e.g. primary cells) for a larger screen and wish to focus on highly conserved microRNAs. It can be used in either human or mouse models, and translates well to in vivo applications.
It includes 386 total mature microRNAs:
302 human and mouse matures that are identical
35 mouse matures in broadly conserved families that are not identical to human
49 human matures in broadly conserved families that are not identical to mouse
Broadly conserved families as defined at www.targetscan.org