GeneArt® Strings™ DNA Fragments

A. GeneArt® Strings™ DNA Fragments are custom-made, linear, double-stranded DNA fragments up to 3 kb in length, ready for cloning in your lab. Please refer to author1.prod.thermofisher.com/strings for full details.

A. GeneArt® Strings™ DNA Fragments are priced in length categories, not per base pair like gene synthesis. The average price is around $0.2 per base pair, so it’s always 20–30% below gene synthesis price.

Product Price
Strings™ DNA Fragments 100–600 bp $99
Strings™ DNA Fragments 601–750 bp $129
Strings™ DNA Fragments 751–1,000 bp $149
Strings™ DNA Fragments 1,001–1,250 bp $219
Strings™ DNA Fragments 1,251–1,500 bp $259
Strings™ DNA Fragments 1,501–1,750 bp $299
Strings™ DNA Fragments 1,751–2,000 bp $349
Strings™ DNA Fragments 2,001–2,250 bp $399
Strings™ DNA Fragments 2,251–2,500 bp $449
Strings™ DNA Fragments 2,501–2,750 bp $499
Strings™ DNA Fragments 2,751–3,000 bp $549

Error correction is done by an enzymatic step during PCR amplification of GeneArt® Strings™ DNA Fragments. We cannot disclose the enzyme we use due to proprietary information.

GeneArt® Strings™ DNA Fragments are amplicons (PCR amplificates) of assembled oligonucleotides; an intermediate product of the gene synthesis production process. This process results in a pool of fragments, and cloning and screening need to be carried out to identify the correct clone. To help ensure that correct fragments are present in the PCR product, GeneArt® Strings™ DNA Fragments are bulk sequence-controlled before shipment. GeneArt® Strings™ DNA Fragments are only sent to customers if we can verify that the customer desired sequence is present in the fragment pool.

Confidentiality is maintained at our facility by strict adherence to customer confidentiality policies, ensuring all production is carried out in-house using the same procedures for GeneArt® gene synthesis.

Yes, you can simply paste your desired sequence into the portal editor (or Excel order sheet if you prefer to order outside the portal) and order without optimization or any sequence modification.

If you do not change any parameter, the algorithm delivers the same result for a given input. However, we do constant improvements based on our research and literature data on our algorithm that may lead to different results if you optimize at different time points.

No. The amino acid sequence is not changed by gene optimization

GeneArt® Strings™ DNA Fragments are double-stranded DNA molecules, it is not possible to order complementary single strands. We recommend ordering one larger sequence instead of several shorter ones for assembly, since this will be less work for you.

There was no specific difference, this just exemplifies the range of results you can have. 100% cloning efficiency just means in this case we found all colonies we screened by colony PCR to have the correct length.

Yes, GeneArt® Strings™ DNA Fragments are delivered as double-stranded blunt PCR fragments and you need to digest to get the desired overhangs or PCR amplify to get the A-overhangs for TA cloning. No need for any modification for TOPO® cloning, but here we recommend to add 5–7 nucleotides of stuffer sequence to protect the ends against naturally occurring truncations and to increase the chance of obtaining full-length clones.

The sequence correctness (or fidelity) is high, but depends on the length of the fragment. You will find one correct clone with high likelihood if you stick to the screening recommendations given on the webpage: sequence 2–4 full-length clones for sequences up to 1 kb, 3–5 full-length clones for sequences 1–2 kb, and 4–8 full-length clones for sequences 2–3 kb. Full-length clones can be identified by colony PCR on the picked clones.

GeneArt® Type IIs Assembly

With careful design, approximately 50–80% cloning efficiency can be achieved if pre-cloned fragments are used in the assembly reaction. The efficiency may be affected by multiple factors such as nature of sequence, DNA purity, etc. 

See examples

The GeneArt® Type IIs assembly kits have the advantage of seamlessly assembling multiple repetitive sequences and short fragments, unlike what is typically possible with homologous recombination–based assembly kits that are available commercially.

We recommend <2 kb mainly due to the robustness of polymerases on the market. Although we recommend using the GeneArt® Type IIs Assembly Kit for assembling up to 8 DNA fragments plus a vector, totaling up to 13 kb in length, you can use it to create constructs that are up to 20 kb in size; however, the cloning efficiency and the number of transformants will be lower.

The GeneArt® Type IIs Assembly Kits have the advantage of seamlessly assembling multiple repetitive sequences and short fragments. Gibson assembly, while also scarless, depends on the overlapping (homologous) ends of adjacent fragments, so repetitive sequences or fragments with unwanted internal homology may reduce efficiency.

Using fragments sized up to 2 kb each, we expect 50–80% cloning efficiency can be obtained with careful design.

TOPO® TA Cloning® kits are usually only for cloning one fragment into a vector, and usually leaves scars (unwanted sequences), while GeneArt® Type IIs assembly kits can seamlessly assemble multiple fragments.