Isothermal amplification technology places no restrictions on the volume of reagent solution that can be used and allows production of fragments at much higher volumes than PCR
Takara Bio, one of Japan's leading biotechnology companies, announces that using its Ican isothermal gene amplification technology, it has developed a system capable of industrial production of a wide variety of DNA fragments needed to make DNA microarrays.
As the first step, Takara Bio, from the beginning of May, has started sales of about 400 DNA fragments that are useful for the analysis of cytokine gene functions.
Ican (Isothermal and Chimeric Primer-Initiated Amplification of Nucleic Acids) can produce about ten times the volume of DNA fragments per unit volume of reagents than using PCR (polymerase chain reaction) technology.
DNA microarrays are able to monitor the presence and relative quantities of the many genes expressed in cells at a time.
These microarrays are widely used in a range of fields, including diagnostics and other medical areas, fundamental biological research and applied areas.
To produce DNA microarrays, though, it's necessary to produce large quantities of a variety of different probe DNA fragments that are complementary to specific genes to be detected.
One million DNA microarrays require the production of about 0.001g of the required DNA fragments.
Accordingly, spotting 1,000 different types of DNA fragment in this manner would require a total of 1g of DNA fragments.
Production at such a huge scale requires industrial technologies and perspective.
"DNA fragments are to the biotechnology industry what semiconductors are to the electronics industry," said a spokesman from Takara Bio. "Customers will be able to combine Takara Bio fragments in which they are interested to create their own DNA microarrays." DNA fragments can of course be produced in small quantities in the laboratory using the PCR method.
However, this method requires cyclical changes in temperature to amplify the DNA.
Increasing the amount of reagent solution increases temperature fluctuations, which create difficulties in terms of DNA amplification.
Accordingly, the PCR method is not applicable to industrial-scale production of DNA fragments.
In contrast, the Ican method uses an isothermal amplification technology, which places no restrictions on the volume of reagent solution that can be used and presents no problems with regards to increasing the scale of the production system.
In addition to these benefits, this reaction structure allows approximately 10 times the volume of DNA fragments to be created per unit volume of reagents than the PCR method.
This remarkable performance makes the new method ideally suited to industrial-scale DNA fragment production.
The cost to produce 0.001g of DNA fragments using the Ican method is 100,000 yen ($777), whereas producing the same amount of DNA fragments using PCR costs about five times more.
Probe DNA fragments on Takara Bio's DNA microarray series, IntelliGene, are produced using Ican, showing just how well-suited Ican-produced DNA fragments are to DNA microarray applications.
In the future, Takara Bio intends to use the Ican method to produce all the probe DNA fragments it needs to deliver DNA microarray products.
At the same time, by selling these fragments at a reasonable price, the company aims to accelerate the spread of DNA microarray technology.
A total of 10,000 different types of DNA fragment are to go on sale during the current fiscal year and include DNA fragments already incorporated into IntelliGene from humans, mice, rats, Arabidopsis, Escherichia coli bacteria, and others, as well as others that have not yet been incorporated in this manner.
Takara Bio says it DNA production capabilities are second to none, and the company is confident that it can cater to global demand. Sales of 1 billion yen are predicted in three years' time. Prices: 10 mg, 15,000 yen/fragment; 100 mg, 50,000 yen/fragment; 1 mg, 100,000 yen/fragment.
Details: human cytokine genes and related DNA fragments.
The approximately 400 types of gene fragment contain a region specific to that gene, which have low homologousness and base lengths of approximately 300.
DNA fragments are modified by amination so as to allow solidification to take place through covalent binding towards the solid-phase.
