siRNA

RNA interference (RNAi) is the best way to effectively knock down gene expression to study protein function in a wide range of cell types. Traditional RNAi methods for gene knockdown in mammalian cells involved the use of synthetic RNA duplexes consisting of two unmodified 21mer oligonucleotides annealed together to form short/small interfering RNAs (siRNAs). Silencer® Select siRNA and Stealth RNAi™ siRNA improve upon these traditional duplexes by using proprietary chemical modifications to ensure better RNAi results.

siRNA TypeDescriptionTechnologyRecommended Use 
Pre-Designed / Validated (tubes)
Silencer® Select Pre-Designed and Validated siRNAImproved potency and guaranteed knockdown. Modified for improved specificity. Pre-designed siRNAs for human, mouse and rat genes. Validated siRNAs for selected human genes.LNA® modified 21mer duplexesSuitable for all applications.
Particularly good for cell culture and RNAi screening work.
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Stealth Select RNAi™ siRNA and Validated Stealth RNAi™ siRNAModified for serum stability and improved specificity. Pre-designed siRNAs for human, mouse and rat genes. Validated siRNAs for selected human genes.Modified 25mer duplexesSuitable for all applications.
Particularly good for in vivo applications.
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Silencer® Pre-Designed and Validated siRNAPre-designed siRNAs for human, mouse, and rat genes. Validated siRNAs for selected human genes.Unmodified 21mer duplexes
Silencer® Pre-Designed & Validated siRNAs are designed using our first-generation algorithm and DO NOT include any chemical modifications. They are recommended for completing in vitro RNAi studies that were started using Silencer® siRNAs. For new studies we recommend Silencer Select siRNAs.
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Plated
PlateSelect™ RNAi w/ Stealth RNAi™ siRNAStealth RNAi™ siRNA in plated format. Configure plates with pre-designed siRNA or siRNAs designed online with the BLOCK-iT™ RNAi Designer.Modified 25mer duplexesFor Stealth RNAi™ siRNA experiments in plates when 1 to 96+ siRNAs are needed.
Specify your own set of siRNAs using a convenient online interface.
1 nmol per siRNA.
Made-to-Order.
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PlateSelect™ RNAi w/ BLOCK-iT™ siRNABLOCK-iT™ siRNA in plated format. Configure plates with siRNAs designed online with the BLOCK-iT RNAi Designer.Unmodified 21mer duplexesFor unmodified siRNA experiments in plates when 1 to 96+ siRNAs are needed.
Specify your own set of siRNAs using a convenient online interface.
1 nmol per siRNA.
Made-to-Order.
order
Made-to-Order Silencer® Select siRNA LibrariesCustom sets of Silencer® Select siRNAs in 0.1 to 5 nmol sizes. Contact your local sales rep for pricing and ordering information.LNA modified 21mer duplexesFor screening 36 to tens of thousands of Silencer® Select siRNAs.
You pick the gene list or choose one of our functional sets.
Multiple sizes and plating options available.
Contact Sales Rep
Made-to-Order Silencer® siRNA LibrariesCustom sets of Silencer® siRNAs in 1 to 5 nmol sizes. Contact your local sales rep for pricing and ordering information.Unmodified 21mer duplexesLower cost alternative to Made-to-Order Silencer® Select siRNA Libraries, but without some of the performance benefits.Contact Sales Rep
Pre-made Sets/Collections
Pre-Plated Silencer® Select siRNA LibrariesPre-defined sets of Silencer® Select siRNAs targeting the human genome and functional gene classes. 0.25 nmol of each siRNA. Ready for immediate delivery. For screening of pre-defined Silencer® Select siRNA sets such as human kinases, GPCRs, or genome.Order
Pre-plated Silencer® siRNA LibrariesPre-defined sets of Silencer® siRNAs targeting the human and mouse genomes and functional gene classes. 0.25 nmol of each siRNA. Ready for immediate delivery. Lower cost alternative to Pre-plated Silencer® Select siRNA Libraries, but without some of the performance enhancements.Order
Design-Your-Own siRNAs
Stealth RNAi™ siRNAChemically modified siRNA designed using the BLOCK-iT™ RNAi Designer.Modified 25mer duplexesFor genes that fall outside of our pre-designed siRNA collection
Suitable for all applications.
Particularly good for in vivo applications.
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Block-iT™ siRNATraditional, unmodified siRNA designed using the BLOCK-iT™ RNAi Designer.Unmodified 21mer duplexesFor genes that fall outside of our pre-designed siRNA collection.
Lower cost alternative, but without some of the performance benefits of Stealth RNAi siRNAs.
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Custom Designed Silencer® & Silencer® Select siRNAssiRNAs designed using the same algorithms as for our Pre-designed Silencer® & Silencer® Select siRNAs.Unmodifed and LNA® modified 21mer duplexesFor genes that fall outside of our pre-designed siRNA collection.  Suitable for all applications.order
Custom (You Provide the Sequence)
Stealth RNAi™ siRNAModified for serum stability and improved specificity.Modified 25mer duplexesWhen you have an siRNA sequence and need it manufactured.order
Block-iT™ siRNATraditional siRNA. Available with a selection of fluorescent labels and modifications.Your choice of 21-25mer duplexesWhen you have an siRNA sequence and need it manufactured--with or without a label.
Lower cost alternative, but without some of the performance benefits of Stealth RNAi™ siRNAs.
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Custom  & Custom Select siRNA SynthesisTraditional siRNA.  Available with fluorescent labels and LNA® modifications.Your choice of 19-21mer duplexes.When you have an siRNA sequence and need it manufactured, with or without labels and modifications.order
Controls
Stealth RNAi™ siRNA Positive & Negative ControlssiRNA controls for use with Stealth RNAi™ siRNAs. Fluorescent labels available with some.Modified 25mer duplexes. Some with fluorescent labels.Any time you are using a Stealth RNAi™ siRNA.Order
Silencer® Select Positive & Negative Controls siRNAssiRNA controls for use with Silencer® Select siRNAs.LNA® modified 21mer duplexes.Any time you are using a Silencer® Select siRNA.Order
Silencer® Positive & Negative Control siRNAssiRNA controls for use with Silencer® siRNAs. Fluorescently labeled controls available.Unmodified 21mer duplexes.Any time you are using a Silencer® siRNA.Order
Custom Scrambled Negative Control siRNAsiRNA controls for BLOCK-iT™ siRNAs. Match your scrambled negative control to the GC content of your unmodified 21mer siRNA.Unmodified 21mer duplexes.Any time you are using a BLOCK-iT™ siRNA.Order

For more information on choosing an RNAi approach or planning RNAi experiments, please visit our Technical Resources and New to RNAi sections of RNAi Central.