Nanosight has announced that it will hold a webinar on 10 November at 15:00 and 17:00 to discuss a technique it has developed in the area of viral vaccine development and phage therapeutics.
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 25nm can be imaged.
This provides the accurate number/size distributions of a virus preparation that are essential in understanding the efficiency of virus purification, according to the company.
The measurement of monomer versus 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 versus the total viral titre.
It is often found that the infectious viral titre may be as little as 0.1 per cent 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.
The company claims that, as such, the measurement of the infectious viral titre versus total viral titre is valuable information; if this ratio can be improved, a final product can be more effectively produced.
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.
The technique produces real-time movie files of the viruses in solution and, as a result, time-dependant phenomena can be studied both qualitatively and quantitatively.
This may be important when trying to understand the stability of a product with changes in temperature, solution pH or time-related changes in the product by the addition of surfactant or dispersing agents.
Particle count and size distribution are essential measurements when trying to study such events, according to the company.
Nanosight can operate in fluorescence mode (405nm), allowing the technique to be used to specifically label viruses.
This could be suitable when working in unpurified harvest materials where it is important to be able to discriminate between cell debris and virus.
Other potential applications include the staining of viral DNA to discriminate between filled and empty capsids.
Attendees can register for the event via Nanosight's website.
