• Effective—siRNAs meticulously designed for maximum potency and specificity
  • Convenient—Ready-to-use siRNAs in amounts sufficient for hundreds of transfections
  • Reliable—Three or more individual siRNAs per target increase screening accuracy
  • Comprehensive—Available for small gene sets and for the whole human genome
  • Customizable—Custom aliquotting, pooling, and custom libraries available
  • Demonstrated improvements in consistency and reliability of phenotypic result

Request a quote for a pre-defined or custom library

Expedite gene function analysis with libraries of effective siRNAs
Increasingly, researchers are harnessing the power of RNAi to better understand gene function. To support this growing demand, Ambion provides pre-defined and custom sets of premium quality siRNAs—known as Silencer siRNA Libraries—for performing RNAi experiments in human, mouse, and rat cell systems.

siRNA Designs That Maximize Specific Silencing
Silencer siRNA Libraries feature combinations of Silencer Pre-designed siRNAs, and when available, Silencer Validated siRNAs, in 96-well or 384-well plates. The design of each siRNA has been optimized for potent and specific silencing. Indeed, the siRNA selection process yields siRNAs that are effective at low concentrations, enabling screening experiments at 30 nM siRNA or lower, minimizing reagent costs and off-target effects [1-3].

To ensure specificity, the siRNA design algorithm incorporates a rigorous check of all siRNA sequences against the transcriptome of the organism targeted. This process is accomplished via a modified alignment search tool which effectively identifies short regions of sequence alignment that BLAST searches miss. Sequences that have significant regions of similarity to off-target transcripts are eliminated. Also eliminated are sequences that fall in polymorphic regions (e.g., SNPs) and sequences predicted to invoke an antiviral response. In addition, the siRNA design process incorporates stringent rules to prevent off-strand targeting.

Rigorous Quality Control for Results You Can Trust
Ambion synthesizes all siRNAs in house to exacting quality standards. After synthesis using extensively validated and controlled procedures, each RNA oligonucleotide is assessed by MALDI-TOF (matrix-assisted laser desorption ionization—time-of-flight) mass spectrometry to confirm siRNA identity and quality. After annealing, each siRNA duplex is analyzed by nondenaturing gel electrophoresis to confirm proper annealing. And to follow each siRNA from order to delivery, Ambion uses a proprietary, state-of-the-art electronic tracking system. The result is premium quality siRNA you can trust.

Pre-defined siRNA Libraries Plated to Order

Pre-defined, made-to-order Silencer siRNA Libraries are available for the human genome, druggable human genome, and dozens of gene functional classes. Mouse and rat siRNA libraries are also available in this format. To create these siRNA libraries, the Life Technologies bioinformatics team uses PANTHER ( and Gene Ontology™ annotation information to create up-to-date target gene sets. siRNAs targeting the collection are then plated to order (minimum 1 nmol), giving you not only the most up-to-date siRNA libraries, but also the freedom to customize your library so that it is most convenient for your particular experimental setup. Want to add siRNAs to your collection? No problem! Life Technologies can also provide siRNAs in 96-well or 384-well plates, deliver multiple aliquots of each plate, arrange siRNAs in custom configurations, and provide siRNAs individually and/or in pools.

Custom siRNA Libraries—The Ultimate in Flexibility

Do you have a favorite list of genes you would like to target with a collection of siRNAs? Ambion can prepare a custom Silencer siRNA Library to any set of human, mouse, or rat genes. The minimum order is only 36 siRNAs. All you need to supply is a list of genes or transcripts identified by NCBI Entrez Gene ID or RefSeq mRNA accession number. With this user-friendly option, you can specify the order of the siRNAs on the plate, as well as the amount of siRNA per order (1 nmol minimum), number of aliquots of each plate, and the number of siRNAs per target. siRNAs can be provided individually or pooled.

Information to Accelerate Discovery
All Silencer siRNA Libraries, whether custom, pre-defined, or pre-plated, are supplied with full siRNA sequence information, and when available, with siRNA validation data. Also provided on the CD accompanying the siRNA library are gene annotation information, which includes gene symbol, gene name, aliases, NCBI Entrez Gene ID, associated RefSeq mRNA accession numbers, and other accession numbers. Plates are individually barcoded with unique identifiers; this information is also provided with the siRNA and gene information.