deltaDOT to replace plaque assays with deltaTITER
The new deltaTITER kit enables accurate baculovirus quantification in less than an hour, a time saving of around five days compared to the traditional method of using plaque assays.
The baculovirus expression vector system has become an incredibly popular method of producing high-level recombinant proteins, making the measurement of the amount of baculovirus in a protein expression system a crucial workflow component in both research and production laboratories.
Baculoviruses are double stranded DNA viruses that infect many different species of insect and have proved to be a powerful and convenient vector for inducing gene expression in eukaryotic cells.
The baculovirus vector expression system has many advantages over other expression systems used to produce recombinant proteins as the vectors induce high expression levels of proteins that are correctly folded and biologically active.
The process involves introducing a foreign gene into a nonessential region of the circular viral genome via homologous recombination with a transfer vector containing the cloned gene.
The virus then infects the insect cells and the recombinant protein is produced.
Because the system involves engineering a recombinant virus rather than an entire cell line, product development times are slashed with proteins being produced in a matter of weeks not months.
However, the traditional plaque assay method of measuring the amount of baculovirus in a sample is tedious and can take up to five days.
The assay involves applying a dilute solution of the virus to a culture dish containing a layer of the host cells in a very viscous medium that stops convective spreading.
After incubation the areas, plaques, in which the cells have been transformed can be analysed and the number of infective virus particles in the original suspension estimated.
In contrast, the new deltaTITER assay is a kit-based automated system for use with the company’s Peregrine high-resolution molecular analyser.
The new kit is based on a proprietary buffer system which provides excellent reproducibility with 6 per cent relative standard deviation.
This significantly reduces cycle times, enabling scientists working in research and development, QA/QC (quality assurance / quality control) and production phases to concentrate on generating and analysing data rather than monitoring assay incubation.
"The new deltaTITER kit, used in combination with the Peregrine system, has the potential to dramatically speed up the process of generating proteins using the baculovirus expression system” said Dr David McMillan, senior group leader for Protein Production at UCB.
