Posted: October 29, 2009

Registration is now open for a virus webinar from NanoSight: A Novel Viral Titre and Characterisation Tool

(Nanowerk News) NanoSight, manufacturers of unique nanoparticle characterisation technology, announces a webinar on Tuesday 10th November, 3pm UK time and then repeated at 5pm UK time (1000 EST, then 1200 EST/0900 Pacific Time). NanoSight has developed a new technique which is gaining much interest in the area of viral vaccine development and phage therapeutics.
NanoSight’s new homepage from their updated web site
NanoSight’s new homepage from their updated web site.
The technique can image the light scattered from viruses in solution and can calculate their size by tracking their Brownian motion on a virus-by-virus basis, viruses as small as 25 nm can be imaged. This provides the accurate number/size distributions of a virus preparation that are essential information in understanding the efficiency of virus purification. Measurement of monomer vs. aggregates at each step of the purification process can be determined as well as a total viral count.
In live attenuated vaccine the total viral count provided by NanoSight can be used in combination with information from infectivity assays to estimate the infectious viral titre vs. the total viral titre. It is often found that the infectious viral titre may be as little as 0.1% of the total viral count. This results from viruses becoming inactivated in the purification process, poor binding affinity in plaque assays or aggregation in the virus preparation. As such measurement of the infectious viral titre vs. total viral titre is value information; if this ratio can be improved then clearly you can more effectively produce a final product.
For inactivated vaccine, the total viral count as provided by NanoSight becomes essential when determining the immune response to the final product, where infectivity assays cannot be used. In addition the technique produces real time movie files of the viruses in solution and as such, time dependant phenomena can be studied both qualitatively and quantitatively. This may be important when trying to understand the stability of your product with changes in temperature, solution pH or time related changes in the product by addition of surfactant or dispersing agents. Particle count and size distribution are essential measurements when trying to study such events.
NanoSight can operate in fluorescence mode (405 nm), allowing the technique to be potentially used to specifically label viruses. This could be of value when working in unpurified harvest materials where it is important to be able to discriminate between cell debris and virus. Other potential applications include staining of viral DNA to discriminate between filled and empty capsids.
About NanoSight
NanoSight Ltd, of Salisbury, UK, is the world leading provider of instruments for the optical detection and real time analysis of sub-micron particles. The Company supplies unique instruments for nanoparticle analysis in the sub-micron region that go far beyond existing light scattering techniques in the characterisation of polydispersed systems. Founded in 2004, the company currently has approaching 200 systems in service worldwide, having begun commercial sales in 2006.
The Company’s proprietary knowledge and expertise has enabled the delivery of technologies to blue chip companies and universities for direct visualisation of individual nanoscale particles in suspension from which independent quantitative estimation of particle size, size distribution and concentration are immediately obtained.
Source: NanoSight (press release)
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