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eBlocks Gene Fragments

Made for speed

eBlocks Gene Fragments are double-stranded DNA fragments of 300–900 bp in length. They are uniquely suited for high-throughput screening of multiple constructs, especially for antibody discovery scientists who want to obtain DNA constructs quickly and reliably for most cloning applications. Additional downstream applications include enzyme engineering and vaccine research.

  • FAST time to ship (1–3 business days from order confirmation)
  • Budget friendly
  • Low screening effort to find your clone


eBlocks Gene Fragments

Orders require a minimum of 24 fragments per plate. Resuspended in 20 μL of nuclease-free water (concentration: 10 ng/μL). Shipped on dry ice and shipped in 1–3 business days of order confirmation (excluding Fridays).


To achieve the fastest possible shipping time, all items that do not meet QC requirements after the first assembly attempt will be cancelled and refunded. No formal cancellation notice will be sent for these items. However, cancellations will be noted on the item specification sheet.

eBlocks Gene Fragments are double-stranded DNA fragments of 300–900 bp in length that are shipped in 1–3 business days (Table 1). They are uniquely suited for high-throughput screening of multiple constructs. With no adapter sequences to remove, eBlocks Gene Fragments are ready to use.

Table 1. eBlocks Gene Fragments specifications

Length300–900 bp
Error rate1:5000
Shipping time (BD)1–3
Minimum order24 fragments
Yield 200 ng
Volume20 µL*
Concentration10 ng/µL*

* Products shipped in Echo® Qualified Microplates (Labcyte), Matrix® 96-well tube racks (Thermo Fisher Scientific), and FluidX 96-well tube racks (Brooks Life Sciences) will be shipped in 50 µL at 4 ng/µL.
† BD, business days after order confirmation (excluding Fridays). Shipping time is dependent on length and complexity of the eBlocks Gene Fragments ordered. In a few cases, shipping time may exceed the estimated time.

Storage conditions

Short term (<2 weeks)4°C
Long term (up to 2 years)–20°C

Consistent high fidelity

All IDT gene fragments demonstrate a consistent, high sequence fidelity across various lengths, and eBlocks Gene Fragments are no exception (Figures 1 and 2).

effect of error rate on predicted cloning success with eBlocks
Figure 1. The effect of error rate on predicted cloning success. With a median error rate of less than 1:5000, eBlocks Gene Fragments demonstrate a high probability of first-time cloning success. This indicates that IDT Gene Fragments are more likely to give a correct clone the first time than fragments supplied by other vendors at comparable length ranges.
Demonstrated cloning efficiency with eBlocks
Figure 2. Demonstrated cloning efficiency. Compared to a leading provider, eBlocks Gene Fragments showed a significant improvement in cloning efficiency, leading to a reduction in the time and cost to find a correct clone.

Robust and flexible assembly

Thorough quality control testing of each eBlocks Gene Fragment ensures consistently high cloning rates for generating recombinant colonies. eBlocks Gene Fragments are compatible with many convenient cloning and assembly kits. Table 2 demonstrates the number of colonies needed to be picked to have a >90% chance of obtaining a desired clone.

Table 2. Low screening effort is needed for eBlocks Gene Fragments to find the correct clone.

LengthColonies to pick

User guides and protocols

Flyers and brochures

eBlocks Gene Fragments (454 KB)

Frequently asked questions

Sequence Information is secure and confidential at IDT. Please see our Confidentiality Statement for more information. All online ordering steps, including sequence entry and your choice of parameters, are also secure and protected.

We screen the sequence of every gene fragment order we receive to (1) identify any regulated and other potentially dangerous pathogen sequences, and (2) verify that IDT’s gene customers are legitimate scientists engaged in beneficial research.

IDT is among the five founding members of the International Gene Synthesis Consortium (IGSC) and helped to create the IGSC’s Harmonized Screening Protocol. The Harmonized Screening Protocol describes the gene sequence and customer screening practices that IGSC member companies employ to prevent the misuse of synthetic genes. IDT takes the steps set out in the Harmonized Screening Protocol to screen the sequences of ordered genes and the prospective customers who submit those orders.

For more information about the IGSC and the Harmonized Screening Protocol, please visit the website at


In October 2010, the United States government issued final Screening Framework Guidance for Providers of Synthetic Double-Stranded DNA, describing how commercial providers of synthetic genes should perform gene sequence and customer screening. IDT and the other IGSC member companies supported the adoption of the Screening Framework Guidance, and IDT follows that Guidance in its application of the Harmonized Screening Protocol. For more information, please see 75 FR 62820 (Oct. 13, 2010), or