Ultramer® RNA Oligonucleotides

Single-stranded RNA oligos up to 120 bases—desalted and delivered dry, in tubes. Turnaround time is 6–8 business days.

  • Increase specificity in your experiments using longer RNA oligos (60–120 bases)
  • Experience greater flexibility for RNA-related applications, including CRISPR, RNA therapeutics development, and RNA controls and templates
  • Receive guaranteed quantities of 4 nmol, 20 nmol, or 80 nmol
  • Verify the high quality of your oligos with free ESI-MS quality control documentation

Ultramer RNA Oligos

Desalted and delivered dry, in tubes.

Ultramer® RNA Oligo, 4 nmol$6.00 USD / Base60 - 120 BasesOrder
Ultramer® RNA Oligo, 20 nmol$9.00 USD / Base60 - 120 BasesOrder
Ultramer® RNA Oligo, 80 nmol$16.00 USD / Base60 - 120 BasesOrder


Ultramer RNA Oligos are compatible with the modifications listed below.
If your desired modification is not listed, please contact applicationsupport@idtdna.com.

DescriptionUltramer® RNA Oligo, 4 nmolUltramer® RNA Oligo, 20 nmolUltramer® RNA Oligo, 80 nmol
5' Amino Modifier C12$55.00 USD$55.00 USD$70.00 USD
5' Amino Modifier C6$26.00 USD$26.00 USD$32.00 USD
5' Biotin$50.00 USD$50.00 USD$60.00 USD
5' deoxyInosine$10.00 USD$10.00 USD$12.00 USD
5' deoxyUridine$10.00 USD$10.00 USD$12.00 USD
5' 6-FAMTM$65.00 USD$65.00 USD$81.00 USD
5' Phosphorylation$20.00 USD$20.00 USD$25.00 USD
Chimeric DNA bases$0.60 USD$0.60 USD$1.00 USD

IDT has optimized proprietary synthesis methods to deliver high quality, long RNA oligos up to 120 bases. Known as Ultramer® RNA Oligonucleotides, these single-stranded custom oligos can provide increased specificity and improved performance in a variety of RNA-related applications. These include, but are not limited to:

  • Unmodified single-guide RNAs (sgRNAs) for CRISPR
  • Long RNAs for RNA therapeutics development
  • RNA controls for PCR and qPCR

Upon placing an order, you will receive your Ultramer RNA Oligos in 6–8 business days, delivered dry and in tubes. Ultramer RNA Oligos are desalted to remove small molecular impurities and formulated to 4 nmol, 20 nmol, or 80 nmol. As is standard with every IDT oligo, Ultramer RNA Oligos receive complimentary QC via ESI mass spectrometry. Resulting mass spec traces and QC information are available free of charge on the IDT website.

Using the RNA Oligo Entry Tool

  • For entering individual RNA bases, insert “r” before the desired base (rA, rU, rG, rC)
  • To convert an entire oligo from DNA to RNA, enter a DNA sequence and select “Convert to RNA” in the lower right-hand corner of the tool

To meet the needs of researchers around the world, IDT employs an innovative manufacturing process which permits rapid, high-fidelity synthesis of RNA oligos. By pairing a proprietary solid support with optimized RNA synthesis chemistries, our Research and Development team has successfully improved coupling efficiencies throughout the entire RNA synthesis process to enable the construction of long RNAs. This has resulted in consistent coupling efficiencies between 99.0–99.3% for Ultramer RNA Oligos (Figure 1).

coupling efficiency ranges - Ultramer RNA oligonucleotides

Figure 1. The general relationship between percentage of full-length product, coupling efficiency, and oligo length. Coupling efficiency becomes increasingly important with increased oligo length. In long oligos, small changes in coupling efficiency have dramatic effects on full-length yield. The graphs depicts the difference in full-length product for coupling efficiencies of 99.0–99.3% (dark blue) and 98.0–98.5% (light blue).

Mass spectrometry is widely considered to be the gold standard method for oligonucleotide quality control (QC). At IDT, we use a highly sensitive and accurate method known as ESI (electrospray ionization) mass spectrometry to confirm the presence of full-length product. Performing QC on long oligonucleotides is complex, even with a method as precise as ESI-MS. Truncated byproducts of synthesis will obscure the mass spectra, making it difficult to deconvolute and identify the desired species. Our proprietary mass spectrometry methods enable us to confidently QC Ultramer RNA Oligos up to 120 bases (Figure 2). Importantly, we provide ESI-MS quality documentation for every oligo we synthesize.

RNA Ultramer fig. 2A

Figure 2A. QC data demonstrates high purity of a 90mer Ultramer® RNA Oligo. The measured molecular weight of the oligo matches its expected molecular weight, which is determined by the specific oligo sequence. Data generated from ESI-MS instruments at IDT.

RNA Ultramer fig. 2B

Figure 2B. QC data demonstrates high purity of a 120mer Ultramer® RNA Oligo. The measured molecular weight of the oligo is within 0.01% of its expected molecular weight, which is determined by the specific oligo sequence. Data generated from ESI-MS instruments at IDT.