KV3 Vaccine is easily distinguished from the wild type CyHV3 (KHV) virus.
It can be verified by a simple PCR test, using a standard protocol.
In the picture below you can see the different bands of the KV3 – Master seed (MS), Working seed (WS) and KV3 batch vs. the wild type KHV (WT).
We are able to show a large deletion of approx. 300 base pairs within the vaccine viral genome (Mut1). The mutation is stable throughout the passages of the vaccine strain – Master Seed (MS), Working Seed (WS) and final KV3 batch.
The TK gene that appears in the picture remains unaltered and serves as a positive control to show that both WT and KV3 – MS, WS, KV3 are in the test.
There is Genomic deletion in KV3. PCR analysis using the same primer set indicates a deletion within the attenuated vaccine strain when compared to wt CyHV-3. Mut1 primers amplify a 572bp PCR product when assayed with a wt template and a 219bp product with the attenuated strain. This result has been confirmed by sequencing of the
PCR products and is shown to be stable through the master seed (MS), working seed (WS) and final product (KV3).
The TK gene remains unaltered and serves as a positive control (TK primers adopted from Dishon et al. 2007). MW-100bp DNA ladder (NEB #N3231).