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Double-stranded DNA (dsDNA) fragments

DNA fragments for synthetic biology and molecular biology applications. IDT offers a variety of reliable double-stranded solutions to meet your experimental needs.


IDT provides high-quality, high-fidelity, double-stranded gene fragments and genes, that are available for a variety of workflows and applications such as protein evolution, gene construction, and antibody engineering workflows, and more.

  • Trusted for purity and quality
  • Adaptable and flexible to fit your workflow and budget
  • Reliable turnaround time

Use Table 1 to help choose the best double-stranded DNA product for your experiment.

Table 1. Comparison of IDT Gene Fragments.

 eBlocks Gene FragmentsgBlocks Gene FragmentsgBlocks HiFi Gene Fragments
CategoryLinear dsDNA fragmentsLinear dsDNA fragmentsLinear dsDNA fragments
Available lengths (bp)300–1500125–30001000–3000
Median Error Rate1:50001:50001:12,000
Estimated shipping time (business days)




Yield200 ng250–1000 ng1000 ng
ApplicationHigh-throughput screening and antibody discoveryGene construction and controlsPathway design and large constructs

*This estimated shipping time is for tubes only. Plates estimated ship date is 10-15 business days.

† NGS = next generation sequencing

Find your correct clone with minimal screening

Using IDT Gene Fragments may reduce the time and expense of screening colonies compared to fragments from other suppliers. Cloning efficiency is affected by many factors, including the cloning method used, the stability of the cell line and plasmid, vector preparation, and toxicity or stress from expression of coding sequences. The values in Table 2 represent typical screening numbers needed when using a seamless assembly method, such as Gibson Assembly® (Codex DNA) or NEBuilder® HiFi assembly (New England BioLabs), and when issues mentioned above are not significant contributors to error or selection.

Table 2. Approximate number of colonies to screen for a 90% chance of getting a correct clone.

Sequence length (bp)eBlocks Gene FragmentsgBlocks Gene FragmentsgBlocks HiFi Gene Fragments

* N/A = not applicable (IDT Gene Fragments are not available at the lengths indicated)


Are you looking to optimize your sequences? The Codon Optimization Tool provides the best sequence option by screening and filtering sequences to lower complexity and minimize secondary structures.

*RUO—For research use only. Not for use in diagnostic procedures. Unless otherwise agreed to in writing, IDT does not intend for these products to be used in clinical applications and does not warrant their fitness or suitability for any clinical diagnostic use. Purchaser is solely responsible for all decisions regarding the use of these products and any associated regulatory or legal obligations.