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HP Custom siRNA

For efficient gene silencing using high-purity siRNA
  • High-purity siRNA at an economical price
  • Short turnaround times
  • Highly photostable and bright Alexa Fluor labels available
  • Option of a range of modifications

HP Custom siRNA is an siRNA synthesis option that provides for specific siRNA requirements, including siRNA for multiple species, specific splice variants, and non-human, -mouse, and -rat genes.

HP Custom siRNA provides highly pure siRNA in 20 nmol amounts. Available fluorescent labels include Alexa Fluor 488, Alexa Fluor 546, Alexa Fluor 555, Alexa Fluor 647, Cyanine 570, Cyanine 670, fluorescein, and rhodamine dyes. Modification options include amino linkers, thio linkers, and biotin, dabcyl, and phosphate modifications.

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Cat No./ID: 1027423
HP Custom siRNA without modifications
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Custom siRNA, 20 nmol, without modifications
Cat No./ID: 1027424
HP Custom siRNA with modifications
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Custom siRNA duplexes, available at different scales and with a range of modifications
The HP Custom siRNA is intended for molecular biology applications. This product is not intended for the diagnosis, prevention, or treatment of a disease.

Product Details

Alexa Fluor labeled siRNA provides brightest fluorescence.

Fluorescence microscopy of HeLa S3 cells 24 hours after transfection with 100 nM nonsilencing siRNA labeled at the 3' end of the sense strand with different fluorescent dyes.

Easy monitoring of transfection efficiency using Alexa Fluor dyes

Successful RNAi experiments depend on effective delivery of siRNA into cells. Fluorescent dyes are widely used to label siRNA for transfection monitoring and optimization. HP Custom siRNA is available labeled with Alexa Fluor 488, Alexa Fluor 546, Alexa Fluor 555, or Alexa Fluor 647. Alexa Fluor dyes are more photostable and much brighter than traditionally used fluorescent dyes, making Alexa Fluor labeled HP Custom siRNA the ideal choice for monitoring transfection efficiency. Alexa Fluor labeled siRNA transfected into HeLa S3 cells shows 10–100 fold brighter fluorescence than fluorescein- and rhodamine-labeled siRNA (see figure "Alexa Fluor labeled siRNA provides brightest fluorescence"). The increased brightness and longer duration of Alexa Fluor dye fluorescence allow greater flexibility in RNAi optimization or cell-tracking experiments.


HP Custom siRNA is provided as High-Performance–Purity (HPP) grade. HPP-grade siRNA is the optimal siRNA purification grade for efficient gene silencing at an affordable cost. HPP-grade siRNA is synthesized using proprietary synthesis and purification processes, yielding siRNA that is >90% pure. There is no need for further time-consuming and expensive HPLC or PAGE purification. The high-throughput synthesis and purification processes enable fast turnaround times and high yields. Each siRNA duplex undergoes stringent quality control including MALDI-TOF mass spectrometry analysis. HPP Grade siRNA is economically priced allowing the use of highly pure siRNA in all routine RNAi experiments.


HP Custom siRNA provides purified, annealed, and desalted siRNA for effective gene silencing using your siRNA sequence of choice. Custom siRNA is available in individual tubes or 96-well plates. siRNA is provided as a stable duplex and there is no need to deprotect, desalt, quantify, or anneal before use. siRNA duplexes are provided as a lyophilized pellet to ensure stability during delivery. Before use, simply resuspend the lyophilized siRNA in the siRNA Suspension Buffer provided.

A wide range of modification options

HP Custom siRNA is available with a variety of fluorescent labels and other modifications. Alexa Fluor dyes provide superior performance and can be directly substituted for other common dyes. Absorbance and emission maxima for available dyes, as well as dyes that can be replaced with spectrally similar Alexa Fluor dyes, are shown in the tables below. Other fluorescent dyes available include fluorescein, rhodamine, Cyanine 570, and Cyanine 670. HP Custom siRNA may be labeled at either the 3' or the 5' end of the sense strand, and labels do not affect the biological activity of the siRNA. As well as fluorescent labels, many other backbone and base modifications are available including amino linkers, thio linkers, and biotin, dabcyl, and phosphate modifications. Special modifications are also available on request; please contact QIAGEN Technical Service.

Spectral characteristics of Alexa Fluor dyes
DyeAbsorbance maximum (nm)Emission maximum (nm)Preferred replacement for:
Alexa Fluor 488495519Fluorescein (FITC or FAM)
Alexa Fluor 546556573Tetramethylrhodamine, Cyanine 570
Alexa Fluor 555555565Cyanine 570
Alexa Fluor 647650665Cyanine 670
Spectral characteristics of the other available fluorescent dyes
DyeAbsorbance maximum (nm)Emission maximum (nm)
Cyanine 570550570
Cyanine 670649670
Fluorescein (FAM)494518
Tetramethylrhodamine (TAMRA)555580

Highly pure siRNA can be used for a variety of applications, including:

  • Functional genomics and proteomics research
  • Gene expression studies
  • Array analysis
  • Monitoring transfection efficiency and cell-tracking experiments


Design By customer
Format Tube
Guarantee/validation No guarantee
Modification Yes
Scale or yield 20 nmol
Species All
Target sequence provided Already known

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