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TruGrade™ DNA Oligos

Reduce barcode crosstalk in your multiplexed NGS experiments

Quality requirements for synthetic oligos used in next generation sequencing (NGS), such as indexed adapters and barcoded fusion primers, have reached unprecedented heights. While traditional purification methods (e.g., HPLC) can effectively increase the amount of full-length oligo, they are incapable of reducing cross-contamination that can occur in co-synthesized oligos. In contrast to applications where such oligo-to-oligo crosstalk has less impact, the use of indexed adapters containing even low levels of cross-contamination can lead to barcode misalignment and sample misidentification, which may confound experiments attempting to identify rare variants.


TruGrade oligos are manufactured by proprietary methods that have been shown to reduce index crosstalk and increase success of multiplex NGS experiments. With TruGrade oligos, you can:

  • Obtain DNA oligos with cross-contamination levels as low as 0.01%
  • Select from a variety of product options to suit your requirements
  • Experience the quality and turnaround time for which IDT is known

DNA oligos


Ultramer™ DNA oligos


DNA oligos


Ultramer DNA oligos


Product details

TruGrade DNA Oligos

With rapidly increasing throughput of sequencing platforms, sample multiplexing has become a common solution to economically address new sequencing capacities. However, pooling indexed samples into one sequencing run comes with the risk of sample misidentification. While this can be attributed to many experimental factors, crosstalk during oligo synthesis is a major contributor. TruGrade DNA oligos are manufactured using an exclusive production process that reduces the risk of oligonucleotide crosstalk and thereby minimizing the risk of barcode misalignment during multiplexing NGS applications.

The TruGrade synthesis and processing service is available for HPLC-purified DNA oligos and Ultramer™ DNA oligos. They are available in plates and tubes and can be formulated to your specifications. TruGrade DNA oligos can be used in a variety of applications including, but not limited to:

  • Library preparation that incorporates barcoded adapters for multiplexing
  • PCR using barcoded fusion primers for multiplex amplicon sequencing
  • Other molecular biology applications that are sensitive to oligo crosstalk


ParameterHPLC purified DNA oligosUltramer DNA Oligos
Typical cross-contamination10.10–0.50%0.01–0.05%
Synthesis scale100 nmol, 250 nmol, or 1 µmolN/A
Yield delivered Variable 4 nmol or 20 nmol

1 Typical cross-contamination levels were determined using in-house proprietary QC techniques and information from our customers.


Modification typeModificationDNA oligos
(100 nmol, 250 nmol, 1 µmol)
Ultramer DNA Oligos
(4 nmol, 20 nmol)
5′ modifications5′ 5-Methyl dC
5′ Amino Modifier C12
5′ Amino Modifier C6
5′ Biotin
5′ deoxyInosine
5′ deoxyUridine
5′ Phosphorylation
Internal modificationsInt 5-Methyl dC
Int deoxyInosine
Int deoxyUridine
Int Spacer 18
3′ modifications3′ Amino Modifier
3′ ddC
3′ C3 Spacer
3′ Phosphorylation
Modified bases and bonds2′ O-Methyl RNA bases
Phosphorothioate Bond