IDENTITY & INTEGRITY
We regularly perform a variety of tests to verify the genetic identity and integrity of adenovirus products.
In particular, we perform tests such as specific sequence amplification by PCR, DNA sequencing, and restriction enzyme mapping to identify both the transgene of interest and the vector sequences of each product.
IDENTITY TESTING BY RESTRICTION ENZYME ANALYSIS
Advaxia uses restriction enzyme analysis to check the integrity and identity of the genomic structure of the recombinant adenovirus products.
We begin by isolating viral DNA from adenovirus products, then digest the DNA with specific endo-nuclease enzymes chosen based on the vector DNA sequence in order to have a restriction pattern with separate and distinguishable bands. We then run the sample and control digests side-by-side on agarose gel, stain them with SYBR Gold dye. Finally, we compare the resulting restriction fragment patterns of each sample to their respective control digest restriction patterns, to obtain a qualitative confirmation of each sample’s identity.
ANALYSIS USING PCR
We use industry-standard polymerase chain reaction (PCR) techniques to verify the identity of recombinant adenovirus products.
We perform this assay using two sets of primers. The first set of primers anneals in the hexon portion of the adenovirus DNA (the PCR fragment products differ in size from vector to vector.) The second set of primers anneals in the transgene region as well as immediately out of the transgene region, determining the presence of a specific transgene in the adenovirus vector.
We confirm the identity of recombinant adenovirus products by trans-gene and/or full genome sequence analysis.
This whole–genome sequencing of adenovirus products is performed using NGS technology.