Custom Oligonucleotide Synthesis

Desalted custom synthesized DNA oligos are shipped dried down or hydrated according to your specifications. Synthesis scales up to 1 µmol are shipped the next business day. 5 µmol and 10 µmol scales are shipped within 7 business days.

Every oligo is deprotected and desalted to remove small molecule impurities. Oligos are quantified twice by UV spectrophotometry to provide an accurate measure of yield. Standard oligos are assessed by mass spectrometry for quality control (QC).

Custom DNA Oligo Tubes

Enter DNA sequences. Select from hundreds of modifications. Paste multiple sequences from Excel or a text file.

Custom DNA Oligo 96 and 384 Well Plates

For large oligo orders and high‑throughput oligo needs, combine oligos into plates and receive a lower price per base than oligos in individual tubes. Modifications are also available as a discounted price when ordered in plates than with individual standard oligos.

Duplex Oligos

Enter duplexed DNA, one duplex at a time.


2-6 standard desalt DNA oligos premixed in a single tube according to your specifications.
Learn more about RxnReady.


25 nmole DNA Oligo$0.45 SGD / Base15 - 60 BasesOrder
100 nmole DNA Oligo$0.67 SGD / Base10 - 90 BasesOrder
250 nmole DNA oligo$1.00 SGD / Base5 - 100 BasesOrder
1 umole DNA Oligo$2.00 SGD / Base5 - 100 BasesOrder
5 umole DNA Oligo$14.50 SGD / Base5 - 100 BasesOrder
10 umole DNA Oligo$27.00 SGD / Base5 - 100 BasesOrder

Yield Guarantees for Standard Desalted DNA Oligos

At no extra charge, every oligo is deprotected and desalted to remove small molecule impurities. Oligos are quantitated twice by UV spectrophotometry to provide an accurate measure of yield. Mass yield, as measured in Optical density (OD), varies with length and decreases for shorter oligos. All oligos are quality control (QC) checked by mass spectrometry.

The following yield guarantees are valid for oligonucleotides ≥20 bases. For more information on yields, please see the Technical Report, Oligonucleotide Yield, Resuspension, and Storage.

Synthesis Scale Oligo Length Yield Guarantee
25 nmole 15–60 Bases 3 ODs
100 nmole 10–90 Bases 6 ODs
250 nmole  5–100 Bases 15 ODs
1 µmole
5–100 Bases
50 ODs
5 µmole
5–100 Bases
250 ODs
10 µmole
5–100 Bases
500 ODs

DNA Synthesis


$0.00 SGD
RxnReady (premixed)
$15.00 SGD
Mixed Bases
$190.00 SGD
Custom Normalized Tube
$0.00 SGD

Formulation Services and RxnReady (Premixed) Oligos 


Annealing Services

Have complementary oligos annealed prior to shipment. Annealed oligos are supplied dry.

Description100 nmole Duplex250 nmole Duplex1 µmole Duplex
Annealing Fee$45.00 SGD$60.00 SGD$68.00 SGD

Other Custom Preparative Services


Identify, sort, and distribute your tubes more quickly using your own set of customized labels. Using the drag-and-drop label designer, your custom label can include:

  • Sales Information (Purchase Order #, Name, University)
  • Manufacturing Data (Date, Product Name, Sequence)
  • Product Specifications (OD, # Bases, Molecular Weight, TM)
  • Lab Specific Info (Custom notes from your lab)
  • Image or Logo (upload your own, or use one of our stock images)

When you place your oligo order, the custom label option is also available at the bottom of the page.

custom label example

Custom Labels

DNA Oligonucleotide Resuspension and Storage

IDT recommends resuspension in TE buffer rather than water. Oligonucleotides resuspended in water will have less stability and will have to be shipped on dry ice, which is more costly than standard shipping. Stability studies at IDT have shown that oligonucleotides stored in water at room temperature may show some degradation in as little as 60 days. The same studies showed that oligonucleotides stored dry or in TE at room temperature did not show signs of degradation for at least 7 months.

Protocols: Duplexed Oligonucleotides

Annealing Oligonucleotides 
Resuspension of Duplexed Oligonucleotides

Starting Scale and Yield

IDT uses a starting scale, referred to as just “scale”, for the amount of initiating nucleotide used to begin oligo synthesis. However, processing steps such as cleavage and deprotection of the oligonucleotide will reduce the final delivery amount (yield). The addition of modifications, purification and length combinations also all affect the final yield of each oligo, which will always be less than the starting scale. The minimum yield guarantee is given in the shopping cart and in the order confirmation email. To receive more final yield, select a larger synthesis scale. More Info ▶

Purification and Yield

Additional purification significantly improves oligonucleotide performance in demanding applications such as multiplex PCR, cloning, mutagenesis, and antisense/RNAi methods. However, purification will always lower oligonucleotide final yield. HPLC routinely provides 85% purity, while PAGE provides 90% purity. The final yield of a PAGE purified oligo, however, will be less than an HPLC purified oligo. For example, a 250 nmole scale 25mer oligo will yield 8X with standard desalt, but only 2X with HPLC purification and 1X with Page purification. More Info ▶

Tools for Oligonucleotide Analysis and Design

IDT provides a number of free oligonucleotide design and analysis tools in the online SciTools® suite. The suite is comprised of tools for designing assay components as well as determining the properties of any sequence entered. Check out the SciTools Suite website at

IDT Guarantees Quality

IDT has pioneered the use of high throughput quality control methods. We are the only oligonucleotide manufacturer that offers purity guarantees and 100% QC by electrospray ionization (ESI) mass spectrometry, ensuring that only the highest quality products are shipped to our customers. We also offer capillary electrophoresis (CE) and analytical HPLC as routine tools for additional QC on purified sequences. In addition to DNA, IDT has led the effort over the last decade to reduce the cost of high-quality custom RNA synthesis. Through improvements to the traditional tert-butyldimethylsilyl (tBDMS) chemistry and advances in instrumentation, IDT has achieved the highest coupling efficiency in the industry. Only at IDT are customers guaranteed the very best in quality synthesis with free mass spectrometry and CE traces on all purified oligos.

Explore and Learn

Read about IDT products at work in research, get expert application advice, and find answers to common research questions.