ON-TARGETplus SMARTpool

• 产品编号：L-RAT-XX-0020      品牌：Dharmacon       原厂货号：L-RAT-XX-0020
• 产品分类：DNA和RNA纯化 > RNA干扰 > RNAi Oligos > siRNA
• 应用分类：

描述：

• 即开即用，提供任何已收集在NCBI参考序列数据库中的人、小鼠和大鼠基因的siRNA试剂。
• 先进的SMARTselection^TM技术确保产品的功能性和特异性。
• SMARTpool®产品可保证靶基因沉默至少75％。
• 不管是SMARTpool®产品还是单条的siRNA产品，均提供每条siRNA序列信息。
• 全面和灵活的产品形式（siGENOME^TM 或者ON-TARGETplus, SMARTpool®或者单条siRNA）可广泛应用于各个领域的研究。

ON-TARGET修饰增强基因沉默特异性

ON-TARGET修饰方式可以进一步增强许多小鼠和大鼠基因沉默的特异性，在最小化脱靶效应的同时提供了基因沉默实验额外的信赖保证。这种修饰方式抑制了siRNA正义链与RISC的结合，根本上排除了正义链参与的脱靶效应。这种修饰可以确保特异性靶向基因沉默的卓越表现。

 

对反义链（antisense,AS）进行ON-TARGET修饰显著降低了正义链的功能性（见下图），因此，对正义链同样的修饰方式可以完全排除正义链所引发的脱靶效应。这种假设通过基因芯片检测将siRNA正义链修饰后靶向特定基因的结果中得到证实。下图的“heat map”图谱表示siRNA双链在不做任何修饰、正义链修饰或者反义链修饰等情况下的脱靶效应。

 

Figure . Silencing potency of siRNAs containing ON-TARGET™ modifications. (A) Three different siRNAs, targeting human

cyclophilin B mRNA, were individually tested in a) unmodified, b) antisense strand modi-fied, and c) sense strand modified

forms for their ability to direct mRNA degradation in HEK293 cells. In all three cases, unmodified duplexes efficiently silenced the target. When ON-TARGET™ Modifications were applied to the antisense strand (S-*AS), duplex functionality was

eliminated, probably because the antisense strand (the strand responsible for directing gene-specific silencing) is unable to associate with the RISC. In contrast, when the same modifications are applied to the sense strand only (*S-AS), the silencing potency of the duplex is maintained or increased (ns = nonspecific; Control = non-targeting siRNA).(B) A heat map resulting from microarray studies illustrates the off-target expression profile of cells treated with unmodified and modified siRNAs directed against Gene A. Note that in this case, modification of the sense strand eliminates the majority of the off-target signature (illustrated primarily in the boxed region). When only the antisense strand is modified, off-target effects occur (blue = down-regulation, black = no effect, pink = up-regulation). (Heat map data presented with permission from A. Jackson and P.S. Linsley, Rosetta Inpharmatics LLC.) B.

 

 

siRNA产品信息

Dharmacon的siRNA试剂是最全面的基因沉默平台，提供给本行业最先进、最成功和最广泛使用的siRNA试剂，确保全球的科学家可以在最短的时间内从RNA干扰技术中获得巨大的收益。目前为止已涵盖了包括人、小鼠和大鼠三个物种的基因组范围内的所有已知基因，持有最大的潜在功能的siRNA数据库，超过确保沉默81,000（包括人，小鼠，大鼠）个基因的相关siRNA试剂。

 

SMARTpool^® siRNA试剂

 

产品特点：

• 是由SMARTselection^TM技术所设计的四条siRNA双链的混合物；
• 提供混合物中每条siRNA序列信息。
• 即开即用型沉默试剂包括人、小鼠和大鼠NCBI基因序列数据库中的所有基因的siRNA；
• 降低浓度依赖性的非特异效应和脱靶效应
• 独有的SMARTselection技术确保高效、特异性的沉默效果；保证标准条件下沉默基因水平至少75%；超过85％的SMARTpool siRNA试剂的沉默水平可达90%甚至更高。

原厂资料：

The patented ON-TARGETplus modification pattern for specificity, combined with the SMARTselection algorithm for efficient, guaranteed target gene silencing, makes Thermo Scientific ON-TARGETplus siRNA the premium choice for optimal knockdown and reduced off-targets.

ON-TARGETplus SMARTpool and individual siRNAs are available as pre-designed, genome-wide reagents for human, mouse, and rat. Simply search for your gene of interest and choose from the available product formats and quantities.

 Rat ON-TARGETplus siRNAs were redesigned in 2012 (RefSeq v. 54) to ensure complete genome-wide coverage and update siRNAs that no longer target all known variants. As a result, nearly 5000 new genes have been added to the collection, and over 3000 siRNAs were reversioned to more completely target known gene variants for more efficient knockdown.

Highlights
• Off-targets reduced by up to 90% compared to unmodified siRNA
• Guaranteed silencing by SMARTpool and 3 of 4 individual siRNAs (see Specifications tab)
• Sequence information provided with siRNA purchase

A two-stranded mechanism requires a two-stranded solution

Dharmacon scientists and collaborators demonstrated in 2006 (see Reference 1) that siRNA off-targets are mediated by antisense seed-region interactions, initiating the development of a dual-strand modification pattern:
• Sense strand is modified to prevent interaction with RISC and favor antisense strand uptake
• Antisense strand seed region is modified to destabilize off-target activity and enhance target specificity

Seed-region analysis on siRNA designs reduces miRNA-induced off-targets

A landmark publication (see Reference 2) from the Thermo Scientific Dharmacon research group was the first to experimentally demonstrate the key role of the seed region in mediating off-targets. A subsequent 2008 paper (see Reference 3) showed the importance of seed frequency in the 3’UTR as in indicator of its likelihood to cause off-targets. These principles were subsequently applied to our siRNA designs to improve specificity:
• Design filters eliminate common seed regions likely to cause miRNA-like off-targets
• Seed frequency analysis for siRNA designs minimize off-target effects

Available Product Formats
•SMARTpool: A mixture of 4 siRNA provided as a single reagent; providing advantages in both potency and specificity. siGENOME and ON-TARGETplus guaranteed to silence by 75% or better (see Specifications).
•Set of 4: A convenient option for purchasing aliquots of all 4 individual siRNAs targeting a single gene. Three of four siGENOME and ON-TARGETplus siRNAs are guaranteed to silence by 75% or better (see Specifications).
•Set of 4 Upgrade: Discounted price on the Set of 4 based on a concurrent or prior purchase of the SMARTpool reagent for the same gene.
•Individual siRNAs: Select 1, 2, or 3 individual siRNAs per gene. Minimum purchase of 4 at the 2 nmol size.