Lentiviral vector-based reagents for RNA interference
Dharmacon lentiviral shRNA products encompass the industry’s broadest, most technologically advanced portfolio of vector-based RNAi reagents for transient, long-term, inducible, and in vivo RNA interference in human, mouse, and rat cells.
Short hairpin RNA (shRNA) sequences are encoded in a DNA vector that can be introduced into cells via plasmid transfection or viral transduction. Because the shRNA expression cassettes can be incorporated into viral vector systems, including lentivirus, they can integrate into the host genome for the creation of stable cell lines. Additionally, when used in combination with one of several viral delivery systems, they can be delivered into difficult-to-transfect primary cells and used for in vivo applications. Based on the delivery method and vector design, vector-based shRNAs can allow for long-term (or inducible) down-regulation of target genes.
The performance of shRNA is influenced by many factors including the efficiency of transduction or transfection, the promoter driving expression of the shRNA and epigenetic modifications (which can lead to silencing of shRNA expression). Further, the influence that each of these factors have on vector performance can differ depending on the cell line or cell type. When planning an experiment using shRNA the available vector options, including; the shRNA design to be used, the vector features (e.g.,promoter), and the method of delivery should all be taken into consideration based on the requirements of the experiment.
shRNA design is typically divided into two formats, the simple stem-loop shRNA and the microRNA-adapted shRNA.
Basic shRNAs are modeled on precursor microRNA (pre-miRNA), and are cloned into viral vectors where they are transcribed under the control of RNA Polymerase III (Pol III) promoters. shRNAs are produced as single-strand molecules of 50–70 nucleotides in length, and form stem–loop structures consisting of a 19-29 base-pair region of double-strand RNA (the stem) bridged by a region of single-strand RNA (the loop) and a short 3’ overhang. Once transcribed, shRNAs exit the nucleus, are cleaved at the loop by the nuclease Dicer in the cytoplasm, and enter the RISC to direct cleavage and subsequent degradation of complementary mRNA.
A microRNA-adapted shRNA consists of a shRNA stem structure with microRNA-like mismatches surrounded by the loop and flanking sequence of an endogenous microRNA. microRNA-adapted shRNAs are transcribed from RNA Polymerase ll (Pol ll) promoters, cleaved by the endogenous RNase III Drosha enzyme in the nucleus, and then exported to the cytoplasm where they are processed by Dicer and loaded into the RISC complex. Studies have suggested that the use of a microRNA scaffold, which is processed by both Drosha and Dicer, may promote more efficient processing and reduce toxicity for in vivo RNAi.
RNA interference and manipulation
Figure 1. shRNA approaches include the introduction of genetically engineered viral vectors or plasmid-based vectors expressing silencing sequences embedded in an endogenous microRNA scaffold (1) or simple stem-loop shRNA (2). Expressed sequences (1 and 2, shown in blue) enter the endogenous pathway at an early stage and are efficiently processed into potent silencing molecules using the endogenous microRNA mechanism. All of these approaches lead to target mRNA cleavage (shown in purple) and gene silencing.
Designed using microRNA scaffold-specific attributes for highly efficient processing via the endogenous RNAi pathway while minimizing off-target potential
Advanced rationally-designed microRNA-based shRNA for human, mouse, and rat genes. Choose from seven constitutive promoters and three reporter options to tailor SMARTvector shRNA for specific cells.
All the benefits of SMARTvector lentiviral shRNAs combined with latest generation of powerful Tet-inducible technology for unprecedented control over gene silencing and reduced off-targeting.
Efficient gene silencing with a microRNA-adapted shRNA design. Available as lentiviral vector constructs or high-titer lentiviral particles for human and mouse
Inducible shRNA expression allows for tightly regulatable RNAi experiments. Available as lentiviral vector constructs for human.
High-titer pooled screening libraries of constitutive shRNAs for pre-defined gene libraries in human, mouse, and rat
High-titer pooled screening libraries of inducible shRNAs for pre-defined gene libraries in human, mouse, and rat.
High-titer pooled screening libraries of constitutive shRNAs for pre-defined gene libraries in human.
Select from a range of our algorithm-optimized reagents to develop the ideal pooled lentiviral screening resource for CRISPR-Cas9 knockout or RNAi knockdown screens.
Offers a classic hairpin, rules-based shRNA design utilizing a simple hairpin of 21 base pair sense and antisense stem, and a 6 basepair loop
Lentiviral shRNA collection from The RNAi Consortium (TRC) with coverage in human and mouse.
Critical to any gene silencing experiment, shRNA controls enable accurate interpretation for reliable, reproducible results
Positive and negative constitutive shRNA controls with choice of seven promoters and three reporter options.
Inducible expression of positive and negative controls with your choice of four promoters and two reporters
Validated collection of GIPZ positive and negative controls for a well-designed RNAi experiment. Available as glycerol stocks or viral particles.
Positive and negative TRIPZ Inducible Lentiviral shRNA Controls for setting the experimental window.
Positive shRNA control targeting GFP and empty lentiviral vector negative control available as glycerol stocks
Delivered as glycerol stocks in 96-well format; these libraries are ideal for arrayed screening formats to elucidate gene activity and study specific pathways or gene families.
Genome-wide collections for high-throughput shRNA screening
Pre-defined libraries of GIPZ shRNA targeting genes related by function or pathways.
Inducible shRNA expression for regulatable gene silencing
Genome-scale TRIPZ Inducible Lentiviral shRNA library arrayed in 96-well plates
Simple hairpin shRNAs in the pLKO.1 lentiviral vector designed by The RNAi Consortium (TRC)
Pre-defined libraries of TRC shRNA targeting human and mouse genes grouped by families or function and arrayed in 96-well plates
Choose from our predesigned product lines of shRNA and over-expression reagents to build your own custom library.
A pooled lentiviral screen can be performed to identify genes that regulate cellular responses and signaling pathways, or to discover novel gene functions. Pooled screening libraries can consist of as few as 50 constructs up to many thousands. In contrast to the costly automated techniques that are required to screen using individually arrayed reagents, pooled screening libraries allow the researcher to transduce and screen a population of cells within a few tissue culture dishes.
High-titer pooled screening libraries of constitutive SMARTvector Lentiviral shRNAs for pre-defined gene libraries in human, mouse, and rat. Choose from seven promoters and three reporter options to select the best format for your experiment.
High-titer pooled screening libraries of SMARTvector Inducible Lentiviral shRNAs for pre-defined gene libraries in human, mouse, and rat. Choose from four promoters and two reporter options to select the best format for your experiment.
High-titer pooled screening libraries of constitutive GIPZ lentiviral shRNAs for pre-defined gene libraries in human.
Use the table below to assist you in determining the right shRNA reagents for your experimental needs.
*Some promoter options may only be available as custom products or upon request.
**For SMARTvector, GIPZ, and TRIPZ lentiviral shRNAs, at least one out of three constructs is guaranteed to reduce target mRNA levels by 70% or more when used in combination with the appropriately matched non-targeting and positive controls.