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, www.nanosight.com
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.
Attendees may register for the event at NanoSight’s newly updated web
site, www.nanosight.com, where visitors may find detailed applications materials
for biological and non-biological nanoparticles and may register for the latest
issue of NanoTrail, the company’s electronic newsletter.