GeneArt® Strings™ DNA Fragments

At minimum of 200 ng GeneArt® Strings™ DNA fragments are delivered dried, ready for resuspension and direct use.

Strings™ DNA Fragments are delivered dried, ready for resuspension and direct use. Please use Strings™ DNA Fragments immediately after resuspension. For longer storage, resuspended Strings™ DNA Fragments should be dispensed into aliquots and frozen at –20°C. Please avoid freeze-thaw cycles.

The GeneArt® production team performs a biosecurity screen on each sequence entered. In the event your order does not pass this analysis, you will be contacted to determine the best way to proceed.

Ordering through our electronic web order portal is the most convenient way to quickly receive your Strings™ DNA Fragments. We recommend that you first choose a suitable cloning system and then design your DNA Fragments according to that system’s requirements.  You can design your Strings™ DNA Fragments yourself—simply paste the sequence into the order form and proceed to the cart to order. Alternatively, you may want to use the portal’s convenient portal editing and optimization functions.  Depending on your desired cloning system, you may need to modify the 5’ and/or 3’ ends of your sequence to enable proper insertion into your desired vector (e.g., add restriction sites and required buffer nucleotides for conventional restriction cloning).

By their very nature, linear DNA fragments are not entirely free of small terminal truncations. When cloning such fragments by restriction / ligation or recombination methods (involving homologous regions) this is usually no issue. However, if blunt cloning methods (e.g. TOPO) are used, it is recommended to add additional 5-10 nucleotides of random stuffer DNA on both ends of the fragment, preserving functional DNA elements needed for downstream applications.

If your desired gene is longer than 1,000 bp, you will need to assemble the full gene from two or more Strings™ DNA Fragments. In that case, simply add suitable end sequences to support the direct subcloning (optional) and assembly method of your choice and the desired 5’ and 3’ sequences for insertion into your vector. Strings™ DNA Fragments only contain A/C/G/T nucleotides; other nucleotides (e.g., I, U) are not accepted. It is not possible to order degenerate nucleotide positions.

GeneArt® Strings™ DNA Fragments are produced with the same technology used for GeneArt® gene synthesis. DNA fragments up to 1,000 bp in length are assembled from high-quality synthetic oligonucleotides and bulk sequenced to verify that your desired gene is highly represented in the pool.

Experimental data show reliability of >90% for finding a correct clone if you sequence 8 colonies containing full-length inserts. Life Technologies offers several reliable and efficient cloning systems, such as TOPO®, Gateway®, and GeneArt® Seamless Cloning. We recommend that you first choose a suitable cloning system and then design your Strings™ DNA Fragments according to the respective requirements.

Cloning Strings™ DNA Fragments using restriction enzyme cloning

The success rate of conventional restriction cloning was evaluated with more than 1,000 fragments directly taken from our regular gene synthesis manufacturing process. Fragments of different length, from 100 to 500 bp and 500 to 1,000 bp, were subjected to restriction enzyme cloning. Bacterial colonies were analyzed by colony PCR to determine cloning efficiency. Fragments with the expected size were sequenced to determine correctness. The figure shows the percent of correct fragments determined from up to 4 (90%; 100-500 bp) or up to 6 (85%; 501-1000 bp) colonies with respect to correct fragment length as determined by colony PCR (97% and 96% respectively) and correct sequence (90% and 85% respectively)

Cloning Strings™ DNA Fragments using TOPO® cloning

Thirty Strings™ DNA Fragments fragments were subjected to Zero Blunt® TOPO® PCR cloning directly after manufacturing. Eight bacterial colonies for each construct were picked and analyzed by colony PCR and sequencing. The figure shows the percentage of correct clones (sequences) for each analyzed Strings™ DNA Fragment. The overall correctness of fragments from 544 bp to 807 bp results in reliability of >90% for identifying at least one correct clone if 8 colonies are sequenced (in our example, 100% of fragments resulted in at least one correct clone).

What are Strings™ DNA Fragments?
GeneArt® Strings™ DNA Fragments are custom-made linear, double-stranded DNA fragments up to 1,000 bp in length, ready for cloning in your lab. Strings™ DNA Fragments are assembled from synthetic oligonucleotides using the same process developed for GeneArt® high-quality gene synthesis. At least 200 ng of Strings™ DNA Fragments are delivered within 5–7 business days. GeneArt® Strings™ DNA Fragments can be ordered through our electronic web order portal and offer a fast and convenient alternative to full gene synthesis that is affordable for every lab.

How are Strings™ DNA Fragments quality-controlled?
Strings™ DNA Fragments are bulk sequenced to assure that your desired sequence is highly represented in the pool. Our experimental data show a reliability of >90% for identifying at least one correct clone if 8 colonies are sequenced. In rare cases, it might be necessary to sequence more colonies to find a correct clone.

Are there any gene editing and gene optimization functions available when ordering Strings™ DNA Fragments?
Yes. We recommend using the electronic web order portal for ordering, where you can use the free, convenient gene editing and optimization functions to adjust the sequence exactly according to your needs (e.g., to add the desired end sequences for subcloning, or suitable sequences for assembly of gene fragments into a larger gene sequence).

After editing and optimization, please check that the final sequences of the fragment(s) are exactly as needed for further processing in your lab (e.g., potential homologous overlaps of the fragments or restriction sites and buffer bases).

Do you offer services for subcloning or assembly of Strings™ DNA Fragments into larger genes?
No, subcloning and assembly services are not available for Strings™ DNA Fragments, as they are designed to offer you the fastest and most affordable way to get access to your genes. If you do not want to clone your gene yourself, we recommend that you order gene synthesis.

How are Strings™ DNA Fragments delivered?
Strings™ DNA Fragments are delivered dried, ready for resuspension and direct use. Freshly resuspended Strings™ DNA Fragments should be used immediately. For longer storage, Strings™ DNA Fragments should be dispensed into aliquots and frozen at –20°C.

Is the delivery time of all three length categories of Strings™ DNA Fragments the same?
Yes. All Strings™ DNA Fragments are delivered within 5 to 7 business days, independent of their length.

Can I order all my genes as Strings™ DNA Fragments instead of ordering gene synthesis?
No. Strings™ DNA Fragments are uncloned and limited to a length of 1,000 bp. If your gene is longer, you will have to assemble it from two or more Strings™ DNA Fragments.
In addition, a sequence may be too complex to be produced as Strings™ DNA Fragment due to repetitions or high GC content. In that case, you’ll receive a message and recommendation on how to order your gene via gene synthesis.

Are Strings™ DNA Fragments always cheaper than gene synthesis?
Yes. Since you need to perform the cloning to obtain your final gene, Strings™ DNA Fragments prices are always lower than those for gene synthesis.