17/07-09   -   Press releases

TwistDx Launches World’s First DNA Amplification Kit Based on Recombinase Polymerase Amplification (RPA)

TwistDx, a developer of point-of-use nucleic acid diagnostics, announced today the launch of its TwistAmpTM product range, the world’s first DNA amplification products based on Recombinase Polymerase Amplification (RPA). Concurrently, TwistDx also launched the TwistaTM portable, real-time fluorometer, an easy-to-use RPA reader. RPA is a proprietary technique, employing recombinase enzymes, used to amplify nucleic acids in any biological sample, with high analytical sensitivity and specificity.

Each of the four currently available TwistAmpTM kits (outlined below) offers scientists the ability to detect DNA molecules in a mixed sample within 10-15 minutes, less than half the time of most PCR systems. Moreover, RPA operates at low, constant temperatures and does not even require initial melting of the sample DNA, opening the way to broader access to end-users without reliance on expensive thermocyclers. RPA has also been shown to be highly resistant to crude samples in comparison to PCR suggesting applications in on-the-spot field testing requiring no nucleic acid extraction.

The TwistaTM portable real-time fluorometer is a customised platform containing proprietary fluorescent probe systems developed by the company to accurately monitor RPA reactions. Although seamlessly integrated with the TwistaTM device, TwistAmpTM kits can be used in combination with various, widely used assay platforms, such as conventional analysis tools (e.g. on agarose gels), dipsticks, as well as broadly available fluorescence plate readers and real-time PCR machines.

“Our TwistAmpTM kit offers researchers a flexible and cost-effective solution to achieve DNA amplification in significantly less time. With laboratory analysis a critical but often time-consuming aspect of biomedical research, we believe these new research tools provide our customers with a viable alternative to PCR, which although very effective is costly to access and time consuming," said Dr. Niall Armes, CEO of TwistDx. “In particular, real-time PCR devices are very expensive; a laboratory could purchase multiple TwistaTM devices for the same price. Field researchers may also be able to easily perform their measurements in a mobile setting as TwistAmpTM enzyme and nucleotide mixes are provided in a freeze-dried form that demonstrates good stability at ambient temperatures. The TwistaTM device will be available with portable battery pack and standalone software."

Notes to Editors

The TwistAmpTM product range can be ordered through the TwistDx website (www.twistdx.co.uk). Details of each product can be found below:

TwistAmp TM Basic

The TwistAmpTM Basic kit contains all enzymes and reagents necessary for the amplification of DNA. Primers and the template must be supplied by the user. Amplification success is typically assessed by an end-point method, such as gel electrophoresis. Amplified material can also be purified and used for down-stream applications (e.g. subcloning).

TwistAmpTM exo

The TwistAmpTM exo kit is recommended for users who want to combine the TwistDx amplification technology with the company’s proprietary fluorescent exo GapProbeTm in a homogenous format. In addition to the basic components, it contains a powerful nuclease (Exonuclease III) which processes exo GapProbeTm during the amplification reaction and generates a real-time read-out. The presence of Exonuclease III reduces the final overall yield of amplified material at endpoint and so is not suitable for analysis on gels, however it is the preferred system for generating strong fluorescence signal kinetics in the RPA system.

TwistAmpTM nfo

The TwistAmpTM nfo kit is designed for users who want to detect the success of their amplification reaction by means of end-point ‘sandwich-assays’, such as lateral-flow (LF) strips. Besides the basic amplification reagents, it includes a nuclease (nfo) that can generate new polymerase extension substrates within suitable LF GapProbeTm. The amplified material can then be used in instrument–free detection formats. The TwistAmpTM nfo kit can also be used for fluorescence monitoring using fluorescent exo GapProbeTm as an alternative to the TwistAmpTM exo kit as nfo processes these probes (often with slightly slower kinetics) and will in addition permit product to be analysed by gels at endpoint.

TwistAmpTM fpg

The TwistAmpTM fpg kit is tailored for users who want to combine the TwistDx amplification technology with an alternative TwistDx reporter probe system, fluorescent fpg GapProbeTM, in a homogenous format. These probes have less design constraints than exo GapProbeTm, although kinetics of fluorescence accumulation may be slower. In addition to the basic components it contains a powerful nuclease (fpg) that processes fpg GapProbeTm during the amplification reaction itself and generate a real-time read-out. The presence of fpg will not reduce the final overall yield of amplified material, in contrast to the use of Exonuclease III in the TwistAmpTM exo kit, allowing end point gel analysis, but the kinetics of probe cutting can be slower than that with the exo system.

TwistAmpTM RT

The TwistAmpTM RT kit will contain all enzymes and reagents necessary for the amplification of RNA – all that has to be supplied by the user are the primers and the template.

TwistaTM portable real-time fluorometer
The TwistaTM portable real-time fluorometer is a customised device developed for monitoring RPA reactions containing TwistDx’s fluorescent probe systems, exo GapProbeTm, fpg GapProbeTm, or intercalating dyes should they be employed. The TwistaTM contains a heated incubation chamber for a strip of 8 tubes perfectly designed for the RPA reagents supplied in the TwistAmpTM kits, and can monitor fluorescence in real-time in two colour channels with exquisite sensitivity. The TwistaTM has a small footprint and can be rendered entirely portable with the addition of a rechargeable battery pack. Data can be analysed by PC-link, or alternatively the device can function as a standalone unit capable of storing and running user-defined methods to call samples positive and negative for any characterised assay.

About TwistDx

TwistDx, Ltd., based in Cambridge, UK, is a privately-held diagnostic company that is developing novel tests based on breakthrough DNA amplification technology. These tests retain the highest possible levels of specificity and sensitivity, while adding extraordinary speed and portability compared to current DNA diagnostics in use. Ultimately the company believes this new generation of tests will provide gold standard DNA testing globally in point of care and field settings. TwistDx’s revolutionary technology, Recombinase Polymerase Amplification (RPA), is positioned to become the DNA-based diagnostic platform of the future, with wide ranging applications in a number of fields, including medical diagnostics, veterinary medicine, industrial applications, agriculture, public health and biosecurity and environmental sensing. More information about TwistDx is available at www.twistdx.co.uk