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Ultramer® DNA Oligonucleotides

Long, high-quality oligos for demanding applications such as cloning, ddRNAi, homology-directed repair, and gene construction

Ultramer DNA Oligonucleotides are generated by proprietary synthesis methods that deliver high quality oligos up to 200 bases. They are available single- or double-stranded and can be delivered in tubes or plates.

  • Complete confidence in oligos that are verified by electrospray ionization-mass spectrometry
  • Unrivalled control of oligo specifications with custom formulation and mixing options


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Ultramer DNA Oligos

Formulated to 4 nmol or 20 nmol guaranteed yield. Shipped dry or resuspended to 100 µM in IDTE buffer, pH 8.0.

Ultramer DNA Oligos

Formulated to 4 nmol or 20 nmol guaranteed yield. Shipped dry or resuspended to 100 µM in IDTE buffer, pH 8.0.


Ultramer DNA Oligos

Shipped dry or resuspended to your specifications. Minimum 24 and 96 oligos required for 96- and 384-well plates, respectively. Orders for fewer than 288 oligos at the 200 pmol scale will incur a fee.



Duplexed Ultramer DNA Oligos

1 oligo pair per well, annealed. Shipped dry or resuspended in duplex buffer. Minimum of 24 and 96 oligos required for 96- and 384-well plates, respectively.


The following annealing fee will be applied to each plate of duplexes:
€ 180,00 EUR

For ordering inquiries, please contact

Ultramer DNA Oligos are long, single- and double-stranded synthetic DNA sequences. They are manufactured with an optimized synthesis platform that achieves consistent coupling efficiencies over 99.5%. With their increased length and purity, Ultramer DNA oligos have increased utility in a variety of molecular biology applications, including (but not limited to):

  • Site-directed mutagenesis—used to efficiently and quickly generate large insertions, deletions or change stretches of sequence identity
  • In vitro transcription—templates for the synthesis of RNA
  • DNA-directed RNAi (ddRNAi)—hairpins are cloned into an expression vector, such as the GeneClip™ U1 Hairpin Cloning System (Promega)
  • qPCR—as DNA standards
  • CRISPR genome editing—as HDR templates

Every Ultramer DNA Oligo you receive will be deprotected and desalted to remove small molecule impurities. In addition, your oligos will be sequence-verified via proprietary ESI-mass spectrometry methods, and quantitated twice by UV spectrophotometry for accurate yield measurements.

Available modifications for Ultramer oligos

Description200 pmol Ultramer DNA Oligo4 nmol Ultramer DNA Oligo20 nmol Ultramer DNA OligoPAGE Ultramer DNA Oligo
AvailabilityPlatesPlates and tubesPlates and tubesTubes
5' Phosphorylation
5' Biotin
5' Amino Modifier C6 
5' Amino Modifier C12 
5' deoxyInosine
5' deoxyUridine
Int deoxyInosine
Int deoxyUridine
Phosphorothioate Bond
2' O-Methyl RNA bases
3' Amino Modifier  
5' 5-Methyl dC 
Int 5-Methyl dC 
3' Phosphorylation 
Int Spacer 18 
3' C3 Spacer 

IDT proprietary DNA synthesis equipment permits rapid, high quality synthesis of nucleic acids. This platform is adjusted to a lower throughput mode which uses an "extra rich" synthesis cycle for long oligos. Along with this refined synthesis cycle, Ultramer DNA Oligos use a unique solid support that is specifically optimized to synthesize low-yield, high-quality oligos up to 200 bases in length. Overall, these improvements to our already established manufacturing methods allow you to acquire longer, purer oligos for your research. Figure 1 illustrates how we attain the exceptional quality of Ultramer DNA Oligos.

Figure 1. Full-length product received is determined by coupling efficiency. Ultramer DNA Oligos are manufactured on proprietary synthesis platforms that offer higher coupling efficiencies than our standard DNA oligos and industry standards. As seen in the graph, coupling efficiency becomes increasingly important as oligo length increases.

Our proprietary ESI-mass spectrometry methods allow us to confidently provide quality control documentation for your oligos up to 200 bases in length. These QC traces, such as the examples shown in Figure 2, are available online free of charge.

Figure 2. QC data shows high purity of 185 nt and 189 nt Ultramer DNA Oligos. The measured molecular weight of each oligo is within 0.01% of its expected molecular weight. Data generated from in-house ESI-MS instruments.

Application guides

Frequently asked questions

OligoAnalyzer™ tool

Identify oligonucleotide properties, including melting temperature, hairpins, dimers and mismatches

UNAFold tool

Perform secondary structure analysis

Dilution Calculator

Find the volume needed to dilute your oligo stock to a lower concentration

Resuspension Calculator

Find the volume needed to resuspend a dry oligo to a desired concentration


Diverse laboratory configurations and various individual preferences in the field require oligos that can be delivered in unique formats. With the formulation services listed below, you can have your oligos tailor-made to your specific requirements. Learn more »

ProductLabReady (Normalized to 100µM in IDTE pH 8.0)Normalized Tube Fee
4 nmole Ultramer® DNA Oligo€ 1,75 EUR€ 3,50 EUR
20 nmole Ultramer® DNA Oligo€ 1,75 EUR€ 3,50 EUR
PAGE Ultramer® DNA OligoN/A€ 3,50 EUR

Custom quality control

In addition to the free ESI-mass spectrometry analysis that comes standard with your oligos, your project may require one of the analytical services listed below. Learn more »

ProductAnalytical IE-HPLC pH 12.0Analytical RP-HPLCCapillary Electrophoresis Trace
4 nmole Ultramer® DNA OligoN/AN/A€ 34,00 EUR
20 nmole Ultramer® DNA OligoN/A€ 42,00 EUR€ 0,00 EUR
PAGE Ultramer® DNA OligoN/A€ 42,00 EUR€ 34,00 EUR
Description96 well Plate384 well Plate
Entire Plate Capillary Electrophoresis€ 400,00 EUR€ 1.200,00 EUR


If you require oligos that are approved for use in molecular diagnostic applications, or if you are interested in our third-party manufacturing services, please click here.