HP Custom siRNA



HP Custom siRNA 旨在用于分子生物学应用。该产品不能用于疾病诊断、预防和治疗。
HP Custom siRNA with modifications

Cat. No. / ID:  1027424

Custom siRNA duplexes, available at different scales and with a range of modifications
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HP Custom siRNA without modifications

Cat. No. / ID:  1027423

Custom siRNA, 20 nmol, without modifications
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  • 经济的高纯度siRNA
  • 快速获得结果
  • 提供高度耐光、明亮的Alexa Fluor标签
  • 多种修饰可选

Product Details

HP Custom siRNA是根据客户需求合成的siRNA,包括多个物种的siRNA、特定的异构体及非人类、小鼠和大鼠基因的siRNA。

HP Custom siRNA提供高纯度siRNA,规格为20 nmol。荧光标记可用Alexa Fluor 488、Alexa Fluor 546、Alexa Fluor 555、Alexa Fluor 647、Cy3、Cy5、荧光素和罗丹明染料。修饰选择包括氨基-linker、巯基-linker、生物素、dabcyl和磷酸基修饰。


使用Alexa Fluor染料监控转染效率,操作简单

RNAi实验的成功取决于siRNA有效转染至细胞。荧光染料广泛用于标记siRNA,方便监控转染过程和优化转染效率。HP Custom siRNA也可用Alexa Fluor 488、Alexa Fluor 546、Alexa Fluor 555或Alexa Fluor 647标记。Alexa Fluor染料与传统的荧光染料相比,具有更高的耐光性、更明亮。使用Alexa Fluor标记HP Custom siRNA,是监控转染效率的理想选择。Alexa Fluor标记的siRNA转染至HeLa S3细胞,显示的荧光比荧光素和罗丹明标记的siRNA明亮10–100倍(参见" Alexa Fluor labeled siRNA provides brightest fluorescence")。明亮度增强和Alexa Fluor染料荧光持续时间延长,确保siRNA在RNAi的优化或细胞跟踪实验中有更好的灵活性。

See figures


HP Custom siRNA提供High-Performance–Purity (HPP) 级的siRNA。HPP-grade siRNA是优秀的纯化级siRNA,进行基因沉默实验经济高效。HPP-grade siRNA使用专有的合成和纯化工艺合成,得到的siRNA纯度>90%。无需进行耗时、昂贵的HPLC或PAGE纯化过程。每个双链siRNA的制备都经过严格的质量控制,包括MALDI-TOF质谱分析。HPP Grade siRNA是高纯度的siRNA,可用于各种常规的RNAi实验,经济实惠,。


HP Custom siRNA提供纯化、热处理和脱盐后的siRNA,可使用自行选择的siRNA序列有效进行基因沉默实验。用户定制的siRNA可保存于单独的试管或96孔板内。siRNA具有双链稳定性,使用前无需脱保护、脱盐、定量或热处理。siRNA双链以冻干粉形式提供,确保其稳定性。使用前,只需用提供的siRNA Suspension Buffer悬浮冷冻干燥的siRNA即可。


HP Custom siRNA提供多种荧光标签和其他修饰选项。Alexa Fluor染料性能卓越,可直接取代其它常用染料。提供的染料和可用于替代的类似于Alexa Fluor的光谱类染料,吸收和发射光的最大值列于下表。可选用的其它荧光染料包括荧光素、罗丹明、Cy3和Cy5。HP Custom siRNA可标记与有义链的3'或5'端,标记物不影响siRNA的生物活性。可用荧光标记以及其它许多主干和基础修饰,包括氨基连接物、巯基交联剂、生物素、dabcyl和磷酸盐修饰。如需特别的修饰,请联系QIAGEN技术支持。

Alexa Fluor染料的光谱特性
染料 最大吸收光(nm) 最大发射光(nm) 首选替代物:
Alexa Fluor 488 495 519 荧光素(FITC或FAM)
Alexa Fluor 546 556 573 四甲基罗丹明,Cy3
Alexa Fluor 555 555 565 Cy3
Alexa Fluor 647 650 665 Cy5
染料 最大吸收光(nm) 最大发射光(nm)
Cy3 550 570
Cy5 649 670
荧光素(FAM) 494 518
四甲基罗丹明(TAMRA) 555 580



  • 功能基因组学和蛋白质组学研究
  • 基因表法分析
  • 芯片分析
  • 转染效率监控和细胞追踪实验

Supporting data and figures


DesignBy customer
Target sequence providedAlready known
Scale or yield20 nmol
Guarantee/validationNo guarantee


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Gene Expression Analysis (1)


How do I calculate the percentage of silencing with real-time RT-PCR for siRNA?

Please find a detailed description for the calculation of the silencing effect in QIAGEN News article 2006 e14 'Real-time RT-PCR for analysis of gene knockdown by RNAi - controls and calculations'.


FAQ ID -498
I want to start with gene silencing (RNAi) experiments. Do you have informational literature?
The QIAGEN e-News article: "Getting started in RNAi research" will provide useful information. You can access it at the following link: Getting started in RNAi research.
FAQ ID -580
How long is fluorescence detectable in cells after transfection with fluorescently labeled siRNAs?

Cells transfected with Alexa-Fluor labeled siRNA still show detectable fluorescence 72 hours after transfection. Certain Alexa dyes, e.g. Alexa Fluor 546, are detectable up to one week after transfection. By comparison, when labeling siRNA with Rhodamine or Fluorescein, transfected cells should be monitored for transfection efficiency after 3-4 hours.

Since Alexa Fluor dyes are more photostable, more resistant to variable pH conditions while in transit through the cell, and much brighter than traditionally used fluorescent dyes, Alexa Fluor labeled HPP Grade siRNA is the ideal choice for monitoring transfection efficiency.

For data and additional details on using fluorescently labeled siRNA, refer to QIAGEN News article e20, 2004: 'Alexa Fluor labeled siRNA is highly effective for monitoring transfection efficiency'.

FAQ ID -392
How are siRNAs introduced into C. elegans?
Two methods have been used; soaking worms in siRNA is successful and worms can be fed bacteria expressing the siRNA (from a plasmid after transformation). REFERENCES: RNAi in C. elegans: Soaking in the Genome Sequence Hiroaki Tabara, Alla Grishok, and Craig C. Mello 1998. Science 282:430. RH Plasterk and RF Ketting The silence of the genes. Curr Opin Genet Dev, Oct 2000; 10(5): 562-7.
FAQ ID -396
Where can I find the public Smith-Waterman homology search tool that you refer to on your siRNA online design page?

The link below leads to a search tool run by TimeLogic Corporation:

 Smith-Waterman homology search

FAQ ID -562
How many transfections can I perform with 20 nmol of HPP grade siRNA?

The number of transfections you can perform with 20 nmol HPP grade siRNA depends on the plate format used, the Transfection Reagent, and additional optimization requirements for your specific application.

In general, when using the HiPerFect Transfection Reagent in a 24-well plate format with 37.5 ng of siRNA per transfection you should be able to perform at least 6600 transfections.

If you are interested in other siRNA synthesis scales and purification options, please visit the QIAGEN Custom siRNA Synthesis page and our GeneGlobe data base, where you can find a large selection of pre-designed and validated siRNAs targeted at human, mouse and rat genes.

FAQ ID -367
Can siRNA silence bacterial genes?
RNA interference is unique to eukaryotes. Homologues to the genes involved in RNAi have not been found in the genomes of bacteria or archaea. Additionally, prokaryotes express RNase III, a very potent and fast-acting RNase that degrades dsRNA substrates as short as 12 bp.
FAQ ID -395
Do we recommend pooling siRNA sequences?
We do not recommend pooling siRNA sequences since this can result in more non-specific and off-target effects diluting the knockdown effect of the silencing siRNA.
FAQ ID -517
Can RNAi experiments be performed in Drosophila?

Yes. Below are a few selected references you can review:



FAQ ID -436
Do I need to anneal, deprotect or desalt my QIAGEN siRNA?

QIAGEN siRNA is delivered as a stable, ready-to-use duplex and does not need to be deprotected, desalted, quantified, or annealed before use. Simply resuspend the lyophilized RNA in the sterile RNAse-free water provided and transfect. Instructions for preparing your siRNA are provided on the data sheet supplied with each siRNA shipment.

FAQ ID -398
Are Northern Blots sensitive enough to detect siRNA-induced gene silencing?

Yes, Northern Blot Analysis has been shown in the literature to detect siRNA-induced reduction of specific mRNA. Whether a Northern Blot will be sensitive enough to detect a mRNA under investigation mainly depends on the expression level of the respective gene in the untreated control.

You can find an example for this application in the reference "Specific inhibition of gene expression by small double-stranded RNAs in invertebrate and vertebrate systems". Caplen et al., PNAS 2001, vol. 98, no. 17, pages 9742-9747.

We recommend to perform real-time RT-PCR for exact quantification of mRNA expression levels.

FAQ ID -403
Do you have a protocol for the fixation of cells transfected with fluorescently labeled siRNA?

For the fixation of cells transfected with fluorescently labeled siRNA, we would suggest to perform the following protocol:

  1. After transfection, remove the medium from the cells and wash the cells once with PBS.
  2. Incubate the cells for 15 minutes at room temperature with 4% Paraformaldehyde (in PBS, pH 7.0). The cells should be completely covered by this solution (e.g., for a 96-well plate use 50 µl solution/well)
  3. Wash the cells with PBS.

Fixed cells can be stored at 4°C for a few days.

(Note: It is also possible to use chamber slides or object slides for this procedure. Object slides should be coated to provide better growing conditions for cells. Cells can be fixed as described above and then overlayed with embedding medium to allow investigation using a fluorescence microscope. Optimal conditions for this method need to be determined by the user)


FAQ ID -793
Where should I add a dye-label modification on the siRNA?

Labeling siRNA duplexes with Alexa Fluor dye or other dye labels at the 3’ end or the 5’ end of the sense strand does not influence gene silencing. We generally recommend the 3' end of the sense strand since new data suggests that a 3' end-labeled sense strand minimizes any chance of steric hindrance or interference with RNAi. Literature indicates that a free 5'-OH group on the antisense strand is required for the siRNA to be functional.

See the reference: Chiu Y L, and Rana T M, 2002.  RNAi in Human Cells: Basic Structural and Functional Features of Small Interfering RNA. Molecular Cell, 10, 549–561.


FAQ ID -648
Can I use my own siRNA design?
Yes. If you provide the siRNA target sequence, we will synthesize, the corresponding HP Custom siRNA for you. Unfortunately, we do not offer custom designed and synthesized SureSilencing shPlasmids.
FAQ ID -2897
Where can I find QIAGEN products for a specific gene or gene product?
You can search for specific gene products in the QIAGEN GeneGlobe Database. This easy-to-use, comprehensive Web portal allows you to find information about, search for, and order high-quality products for human, mouse, and rat genes. QIAGEN provides a vast range of gene-specific products covering every aspect of an experiment, from gene silencing to expression analysis at the mRNA or protein level.
FAQ ID -803
How do I submit a siRNA order by telephone or online?

FlexiTube siRNA, FlexiTube GeneSolution, FlexiTube siRNA Premix, FlexiPlate siRNA, and GeneFamily Lists siRNAs can be ordered by catalog number over the telephone.

However, to ensure accuracy, Custom siRNA Synthesis orders should be submitted in writing. Therefore you can use the HP Custom siRNA Order Form https://www.qiagen.com/products/genesilencing/customsirna/customsirnaorder.aspx?EmailOrdering=1.

Visit the RNAi Solutions page http://www.qiagen.com/products/rnai/default.aspx?r=2714 on our homepage for access to the Online Ordering Tool, and choose the order link for your product of interest.

FAQ ID -399
What is the composition of the siRNA resuspension & annealing buffer?
The composition of the siRNA resuspension & annealing buffer is 100 mM Potassium Acetate, 30 mM HEPES-KOH, pH 7.4.
FAQ ID -522
Has RNAi been successful using siRNA in Zebrafish and Xenopus?

Here are examples of references that describe the inhibition of gene expression by siRNA in Xenopus and Zebrafish:

FAQ ID -400
What is the average molecular weight of a siRNA, and how do I convert uM to ug values?
The Molecular Weight (MW) of a 21 nucleotide double-stranded siRNA molecule is approximately 13-15 ug/nmol. The exact MW depends on the sequence of the siRNA. 20 uM of double-stranded 21 nt siRNA is equivalent to approximately 0.25 ug/ul.
FAQ ID -388