Reagent companies sell RNAi reagents as “virtual kits” consisting of the shRNA or siRNA sequences and an appropriate transfection reagent. Vendors usually guarantee that a certain percentage of multiple knockdown constructs they sell for a particular target RNA will succeed. Users can monitor the progress of their knockdown by performing a beforeand- after Western blot to determine if the protein coded by the putative knockdown gene is still being produced.

Top 7 Questions You Should Ask When Buying RNAi Reagents

1. Does the RNAi product provide transient silencing only or does it allow stable gene knockdown? Choice of RNAi products will be determined by whether you need to knockdown expression for several days or create a stable cell line.

2. Is the RNAi product suitable for your cells? How difficult it is to transfect your cells will determine the delivery method you require, such as tailored transfection reagent or lentiviral vector.

3. Ask if a ready-to-use product is already available; has the silencing of your gene(s) of interest already been validated and published?

4. Do the RNAi products guarantee a level of knockdown? What happens if you do not get the amount of gene silencing needed?

5. Are positive and negative controls provided with the RNAi products?

6. Does the RNAi product silence all known splice variants of my gene of interest and does it target the ORF or non-coding region of my gene?

7. How can I minimize the interferon response of RNAi transfection? shRNA instead of siRNA may be an option in some cases.

Five Fast Facts on RNAi Reagents:

• RNAi works by silencing RNA, which is the immediate precursor of proteins implicated in the phenotype of interest. Reagents consist principally of the interfering RNA construct and a transfection agent for introducing the RNA into cells.

• The most commonly used interfering RNAs are the short (19 to about 25 nucleotides) interfering RNAs (siRNAs) and short hairpin RNA (shRNA). Approximately 75 percent of the RNAi reagent market used siRNA, as of October 2011.

• Length is a critical attribute of siRNA and shRNA reagents. In nature, interfering RNA species are usually between 20 and 25 nucleotides in length.

• RNAi may eventually have greater impact on biology than polymerase chain reaction (PCR), although RNAi can be considered more complex than PCR.

• The main obstacle is introducing the interfering RNA sequence into the cell, into the location of the target gene, and then gettin g it to bind to and inactivate the target.

Recently Released RNAi Reagents

Sets of shRNAs Lentivirus
• Guaranteed knockdown: Target the gene of interest and are supplied as ready-to-use lentiviral particles
• Eliminate the need for transfection reagents—just add the lentiviral particles to the cells
• AMSBIO also supplies shRNA lentivector cloning kits, and reagents including packaging plasmids and cells for users to produce their own particles


2’-OMe-I and 2’-OMe-T Modified Phosphoramidite Ranges
• New RNA-type phosphoramidites provide nuclease resistance and stability
• New ethyl phosphoramidites improve oligonucleotide stability and delivery into cells, making them ideal for therapeutic applications
• Ideal for triplex, antisense and gene targeting studies, as they form more stable hybrids with complementary RNA strands compared to equivalent DNA or RNA strands

Link Technologies

Epicentre Ribo-Zero rRNA Removal and Gold Kits
• Remove cytoplasmic and mitochondrial RNA
• Deliver enhanced profiles of RNA-seq libraries
• Achieve results in a time-saving single-pass process
• Available exclusively in the UK from Cambio
• Compatible with ScriptSeq preparation kits


10mL Disposable Multichannel Reagent Reservoir
• Low dead volume (650μL) generates significant savings on reagent usage
• Pour back spout helps control liquid flow allowing users to neatly and easily return excess fluid to a source container • Now available in 10mL, 25mL, and 100mL sizes
• Packaging options include portable, standalone sleeves and individually sealed bags for sterile applications


RNAi Reagent Manufacturers

Integrated DNA Technologies
Link Technologies
Luminex Corporation
NanoString Technologies
SPEX CertiPrep
Thermo Fisher Scientific, Dharmacon