At the end of June, Izon launched its full version products, our qNano and qViro instrument systems; the world’s first commercially available nanopore technology platforms for the measurement and characterisation of nanoparticles.

The launch was held at NZi3, the national ICT Innovation Institute based at the University of Canterbury, Christchurch, New Zealand. The Honourable Dr Wayne Mapp, Minister of Research, Science and Technology, Christchurch Mayor Bob Parker as well as over 100 science and business people from both New Zealand and overseas attended the launch.

The event was covered by TVNZ including a business news feature which you can view on their website.
The ease of use and real-time detection features of the technology were showcased in a light-hearted world-first, the inaugural World Nanoparticle Counting Championships.

Since the launch over 20 instrument systems have been dispatched to research groups.  We now have instruments in 12 countries around the world.

Associate Professor Birgitta Knudsen from the Molecular Biology department of Aarhus University in Denmark reports on her group’s application of Izon’s qNano instrument system to cutting edge prognostic research...

Besides being of importance for the regulation of genome topology in all living organisms, DNA topoisomerases are of substantial clinical interest, being the primary cellular target of numerous anti-cancer chemotherapeutics. The anti-cancer effect of current drugs correlates directly with the intracellular topoisomerase activity levels. Precise and highly sensitive means of measuring topoisomerase activities in clinical samples will be highly valuable for cancer prognostics.

The aim of this project is to use the qNano to quantify DNA topoisomerase activities at the single molecule level for cancer prognostic purposes. Mechanistically, DNA topoisomerases act by introducing enzyme bound breaks in the DNA backbone, which are followed by rapid ligation that restores the integrity of the DNA. We have utilized this mechanism of action to detect topoisomerase activities in terms of circularization of linear DNA substrates, followed by rolling circle amplification and visualization of the resulting rolling circle products (RCPs) by hybridization to fluorescent probes and microscopic analysis [1]. However the microscopic readout, poses limitations to the sensitivity of the assay. The RCPs (varying in size from 600-1000 nm) are easily detected using the qNano, which holds great promise for an increased sensitivity of the basic topoisomerase activity assay.

For more information on this research please visit the group website.

[1] “Single-Molecule Detection of Human Topoisomerase I Cleavage-Ligation Activity” Stougaard et al., ACS Nano, 3(1), pp 223-233 (2009)

Serious research with a fun side: “Can we have it in pink please...?”

An outline of Oxford University researcher Lijun Wang’s application of Izon’s qViro instrument system for quantitative concentration analysis of adenovirus samples...

The single particle detection element of Izon’s qViro system allows individual virus particles to be counted one at a time as they traverse the nanopore. The tunability of the nanopore allows the system settings to be optimised to measure a wide range of particles with different size or surface charge

In this study, a range of adenovirus sample concentrations were measured to demonstrate the ability of the system to relate frequency of particle translocation to viral titre.

The figure below demonstrates that the measured frequency of translocation events for adenovirus is linearly related to the viral concentration in the solution. The adenovirus samples were run at a variety of applied bias voltage and nanopore stretch values showing that the linearity of the relationship holds under different setup conditions. As a result the nanopore may be tuned to the most favourable measurement conditions for adenovirus (to maximise signal to noise ratio) whilst maintaining the frequency–concentration relationship. An experimentally determined linear relationship for adenovirus at a given set of measurement conditions can be used to determine the concentration of an unknown solution of the same virus through simple measurement of count rate.

This work is part of a larger body of study currently being compiled for submission to Journal of Virological Methods. Reference details will be provided on our website in the future.

Izon’s founding scientist Dr Murray Broom demonstrates the potential of the Izon technology platform to monitor binding events in real time...

The Izon measurement systems offer a method for studying binding interactions between nanoparticles. To observe nanoparticle interactions, the components may be pre-incubated and after a set time analysed using the nanopore. Alternatively, the reactants can be combined in the upper fluid cell of the instrument and the electrophoretic properties analysed in real-time while they react. Suitable interactions that might be observed using the nanopore include those between antibodies and an antigen, the binding of ligands to receptor complexes, particle-particle aggregation and nonspecific adsorption of solutes onto particle surfaces.

By analysing the variations in blockade event data from the constituent particles and the bound complex, one can:

• confirm the occurrence of a binding interaction
• compare properties of the two samples for example variation in the distribution of particle sizes or detect the presence of aggregates that may have formed upon binding
• detect the presence of molecules that may otherwise be below the detection limit of the instrument
• monitor the binding interaction event in real-time particle-by-particle by combining the reactants in the top fluid cell of the instrument

Experiments carried out by Izon’s founding scientist Dr Murray Broom provide an example of this capability. The graph below shows changes in the measured blockade duration due to the binding interaction of avadin (approximately 3 x 4 x 6.5 nm) with carboxylated polystyrene nanoparticles (184 nm ± 8.5).

Behind the clean lines and crisp exterior of the Izon instrument systems lies world class electronic and software solutions for detection and analysis of tiny variations in current. In this feature Izon’s lead software developer Dr Martin Jones provides an insight into key upcoming developments for the Izon Control Suite Software...

In Izon’s qNano and qViro instrument systems, the software plays a key role; controlling the device as well as capturing and translating variations in the baseline current from blockade events into meaningful data for the end user.

The focus of the control system development program thus far has been on implementing core system functionality. This initial work is now in a phase of optimisation and stabilisation that will see a series of functional improvements delivered to our customers. The focus of these developments is on delivering an improved user experience.
The next version release (V1.1) will be at the end of November and includes:

• Signal optimisation for smaller particles - improved signal to noise ratio in the 50nm particle size range
• User controls to select for the detection of resistive pulses, conductive pulses or both
• Signal dashboard providing a summary view of the signal data stream that can be used to monitor signal parameters of the data being collected for later analysis

We are always keen to hear from our end users and our aim is to pursue software development in directions that is of most benefit. For current customers there is a ‘Request Feature’ function in the software that you can use to directly contact us if there is a software function that you would like developed.

We regularly attend international conferences and tradeshow, providing a great opportunity for you to meet us in person and experience our technology first hand...

We are committed to providing as many people as possible with the opportunity to see our instrument systems in action - over the past year we have attended conferences, tradeshows and other events in half a dozen countries including local events in New Zealand and Australia as well as major conferences and tradeshows in the USA, Canada, Germany and Singapore.

Our next presence will be at the Biotechnology Business Exchange (BBE) Conference in London, 9th - 11th December 2009 followed by the International Conference on Nanoscience and Nanotechnology (ICONN), in Sydney Australia, 22nd - 26th February 2010. For more information on these and other upcoming events please see our website.