ppt

1. VIRUS
NEUTRALIZATION
TEST
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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
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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
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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
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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.
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6. VNT cont..,
• Expectations
• No Ab(in serum)+virus no neutralization
CPE
• Ab(in serum)+virus neutralization No CPE
• Cells remain intact
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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.
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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.
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9. REFERENCES
1) Carter,J.,and
Saunders,V.(2007).Virology:Principles and
Applications.John Willey & Sons,Ltd.England,UK.
2) 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.2nd Edition.ASM press,Washington
DC,USA.
3) Murphy, F.A.,Gibss ,J.P.,Horzinek.M.C.,and
Studdert,M.J.(1999).Veterinary Virology.2nd
edition.Elsevier,Inc.Califonia,USA.
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10. THANKS FOR YOUR ATTENTION
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