Virus neutralization test

ppt

1. VIRUS NEUTRALIZATION TEST SHAREEF NGUNGUNI 4/19/2017 1

2. VIRUS NEUTRALIZATION TEST Introduction Serological method that detects the presence of viral neutralizing antibodies. The antibodies bind to the viral particles Monoclonal and polyclonal antibodies Block viral infectivity-No cell infection SHAREEF NGUNGUNI 4/19/2017 2

3. VNT cont.., VNT are conducted by : mixing dilutions of antibodies with standardized amount of virus, incubating them and cultured into cells, eggs or animals to have a clear cytopathic effect observation CPE effects: Rounding of cells Change in texture- granular/hyaline/glassy Formation of syncytium SHAREEF NGUNGUNI 4/19/2017 3

4. VNT cont.., STEPS First step: Serial dilutions of serum(virus-neutralizing Ab ?)+ known virus Incubated for 1-2hr at 37 degrees Celsius Second step; Cell culture inoculated with mixture Seal the plates & Incubated at 37 degrees Celsius Direct microscope SHAREEF NGUNGUNI 4/19/2017 4

5. VNT cont., Illustrations using diagrams Copyright 2009, John Wiley & Sons, Inc. Copyright 2009, John Wiley & Sons, Inc. Copyright 2009, John Wiley & Sons, Inc. . right 2009, John Wiley & Sons, Inc. 4/19/2017 5 SHAREEF NGUNGUNI

6. VNT cont.., Expectations No Ab (in serum)+virus no neutralization CPE Ab (in serum)+virus neutralization No CPE Cells remain intact SHAREEF NGUNGUNI 4/19/2017 6

7. VNT cont.., -pro’s: Can be specific Sensitive Vaccine production/immunological studies -con’s: Very slow(days) Intensive Require skilled people Depend on cell line- use of wrong cell lines may assume that the antibodies have neutralization ability when not, or may seem to be ineffective when they actually have the neutralization abilities. SHAREEF NGUNGUNI 4/19/2017 7

8. Conclusion All in All, viral infections can be diagnosed in laboratory by many methods and the gold standard one is neutralization tests since it is a technique to which all other test methods have been compared with. Although the technique is highly sensitive and specific in detection of antibodies, it has disadvantages. SHAREEF NGUNGUNI 4/19/2017 8

9. REFERENCES Carter,J.,and Saunders,V .(2007). Virology:Principles and Applications. John Willey & Sons,Ltd.England,UK . Flint,S.J .,Enquist,L.W.,Racaniello,V.R.,and Skalka,A.M .(2004). Principles of virology:Molecular Biology,Pathogenesis and Control of Animal Viruses.2 nd Edition.ASM press,Washington DC,USA. Murphy , F.A., Gibss , J.P.,Horzinek.M.C.,and Studdert,M.J .(1999). Veterinary Virology .2 nd edition.Elsevier,Inc.Califonia,USA . SHAREEF NGUNGUNI 4/19/2017 9

10. THANKS FOR YOUR ATTENTION SHAREEF NGUNGUNI 4/19/2017 10