Long, custom RNA oligos—Ultramer RNA Oligonucleotides

Product spotlight: Use Ultramer RNA Oligonucleotides to increase specificity and improve performance in a variety of RNA-related applications. Learn more about these high-quality, single-stranded custom oligos, made up to 120 bases.

Feb 28, 2017

Ultramer® RNA Oligonucleotides are single-stranded RNA oligos up to 120 bases that are desalted and delivered dry in 6–8 business days. With longer RNA oligos from IDT, you can:

  • Increase flexibility in applications requiring long synthetic RNA, including CRISPR and RNA therapeutics development
  • Create more complex RNA controls and templates
  • Select from guaranteed quantities of 4 nmol, 20 nmol, or 80 nmol
  • Verify the high quality of your oligos with free ESI-MS quality control documentation

Coupling efficiency in oligonucleotide manufacturing refers to the success rate of a synthesizer adding new bases to a growing nucleic acid chain. This measure is especially important in long oligo synthesis, because as the length of an oligo increases, small differences in coupling efficiency have dramatic effects on the amount full-length product produced.

By using Ultramer RNA Oligos, you can take advantage of our optimized, proprietary synthesis methods, which facilitate a narrower, higher range of coupling efficiencies and yield a greater proportion of full-length RNA oligo than standard synthesis methods. The graphs in Figure 1 depict the differences in full-length product produced when using Ultramer RNA Oligo synthesis methodology (coupling efficiencies of 99.0–99.3%; dark blue) and standard RNA oligo synthesis (coupling efficiencies of 98.0–98.5%; light blue).

Figure1_Coupling efficiency ranges

Figure 1. Ultramer synthesis technology provides greater yield of full-length RNA oligos than standard RNA synthesis methods.

ESI (electrospray ionization) mass spectrometry methods are used to confirm the presence of full-length product (Figures 2 and 3). You receive free ESI-MS quality documentation for every oligo we synthesize.


Figure 2. QC data demonstrates high purity of 90 nt Ultramer RNA Oligo. Molecular weight was measured by ESI MS and found to be within 0.01% of its expected molecular weight (determined by its specific sequence).


Figure 3. QC data demonstrates high purity of 120 nt Ultramer RNA Oligo. Molecular weight was measured by ESI MS and found to be within 0.01% of the expected molecular weight (determined by specific sequence).

Ordering long RNA oligos

The RNA Oligo Entry Tool makes ordering long RNA oligos easy. There is even a “Convert to RNA” feature that quickly switches an entire oligo from DNA to RNA. Upon placing an order, you will receive your Ultramer RNA Oligos in 6–8 business days, delivered dry, in tubes. Ultramer RNA Oligos are desalted to remove small molecular impurities, and are 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.