Study On Quantitative Determination And Purification Of Porcine Reproductive And Respiratory Syndrome Virus Particles

Porcine reproductive and respiratory syndrome virus is the main cause of the highly infectious porcine reproductive and respiratory syndrome disease characterized by pregnancy sow abortion, piglets respiratory problems and high death rate. Considerable economic losses were induced due to the rapid spread of the disease all over the world. PRRS vaccination can control the epidemic outbreak effectively, so improving the vaccine production technology and virus quantitative determination method is vital. The study focused on virus quantitative determination and purification methods both of attenuated live PRRSV particles and inactivated PRRSV particles provides further insight into epidemic PRRS prevention and vaccine quality test.The results of sucrose density gradient ultracentrifugation applied in virus quantitative determination of attenuated live PRRSV particles showed that the experiments relative standard deviation (RSD) of the same sample test in triplicate was 10%, conforming with Chinese Pharmacopoeia.The data of gel filtration chromatography applied in PRRSV purification indicated that up to 80% cellular proteins were removed and 70% virus particles were collected. The method is suitable for laboratory virus purification of attenuated live and inactivated PRRSV particles, the further study is required to test whether it is applicable in industrial large-scale production.As for quantitative determination of inactivated PRRSV particles, most of the cellular proteins must be removed using gel filtration chromatography, before the determination of the virus particles. The results showed that RSD of the same sample test in triplicate was 15.9%, exceeded the term of Chinese Pharmacopoeia. However this method give a reference to quantitative determination of inactivated PRRSV particles.