• Best knockdown performance in side-by-side tests decreases the chance of missing an important discover
  • LNA® chemical modifications reduce off-target effects by up to 90%, so you spend less time following up on false positives
  • 100% guaranteed knockdown for complete confidence in your reagents
  • Up to 100 fold more potent than currently available siRNAs, so you use less siRNA per experiment
What are Silencer® Select siRNAs?
Silencer Select siRNAs are the next generation Ambion siRNAs. These siRNAs incorporate the latest improvements in siRNA design, off-target effect prediction algorithms, and chemical modifications to yield siRNAs with unrivalled efficacy, potency, and specificity. The result is fewer failed experiments due to poor silencing, and cleaner, more consistent phenotypic data. For more information, including data, brochure, webinar, and FAQs, please visit our Silencer® Select Information Page.

Silencer® Select Pre-Designed siRNAs
Silencer® Select Pre-Designed siRNAs, which are 100% guaranteed to silence their intended target, are immediately available for >98% of genes in the human, mouse, and rat genomes in a purified, ready-to-use format. siRNA sequence information is always provided.

Silencer® Select Validated siRNAs
Silencer® Select Validated siRNAs are individual siRNA duplexes that have been verified experimentally to reduce the expression of their individual target genes. Each siRNA was designed using the same effective algorithm used to design Silencer® Select Pre-designed siRNAs. However, each one has also been functionally confirmed and is guaranteed to reduce target gene expression by at least 80% when measured 48 hours post-transfection. [View Guarantee]

All Silencer® Select Validated siRNAs are annealed and provided ready to use. The included data sheet indicates the extent of mRNA knockdown observed during validation, the exon targeted by the siRNA, and full siRNA sequence information.

Quality Control
Applied Biosystems synthesizes and purifies each Silencer Select siRNA in state-of-the-art facilities to meet the highest quality standards. As part of our rigorous quality control procedures, each RNA oligonucleotide is analyzed by MALDI-TOF mass spectrometry, and analytical HPLC is used to monitor purity. To provide the utmost in quality, we also assess each annealed siRNA by gel electrophoresis to confirm that the strands anneal properly. The result is premium-quality siRNA that is purified and ready to use.

NEW! In Vivo Ready Silencer® Select siRNAs
"In Vivo Ready" Silencer Select Pre-designed and Validated siRNAs—the highest quality siRNAs available anywhere—are subjected to that extra level of purification and testing required for the introduction of siRNAs into animals. After HPLC purification and annealing, each siRNA is further purified using a process that removes excess salt via a semi-permeable membrane. The result is highly pure siRNA with minimal salt content, suitable for in vivo applications. In vivo siRNAs are then sterile filtered and tested for the presence of endotoxin. At a concentration of 50 µM in deionized water, In Vivo Ready siRNAs contain <0.6 mM Na+, <2.0 mM K+, and <0.1 mM Mg2+.

Approximate Turnaround Times *

Standard Purification4 business days
HPLC Purification6 business days (20 and 40 nmol)
15 business days (250 nmol)
In Vivo Ready15 business days (250 nmol)

* Estimated time from order confirmation to ship date from Austin, TX for orders confirmed by 2 pm CST. Does not include time required for shipping (typically overnight for US and Canada deliveries, 2 days for Europe, 2-3 days elsewhere).