II. Definitions
- Neutralization Test
- Antibody or Antigen activity tested through sequential dilution until activity ceases
- Activity test examples include Infectivity in tissue culture, Hemolysis or Agglutination
III. Types
- Plaque Reduction Neutralization Test (PRNT)
- Patient serum sample at sequential dilutions added to known virus sample and then incubated
- Solution of serum and virus are poured over a single layer of host cells and covered with agar
- Concentration of infected cell regions (Plaques) are then measured over several days
- Complement Fixation Test
- Patient serum sample at sequential dilutions added to known virus sample
- Test solution contains complement and RBCs (e.g. sheep RBCs) coated with hemolysin
- Serum-virus solution is added to the complement-RBC test solution
- Antistreptolysin O Titer (ASO Titer)
- ASO Titer is now performed as an Agglutination Test, but was previously a Neutralization Test
- Streptococcus produces streptolysin O which causes Hemolysis
- Test starts by combining streptolysin O with sequential dilutions of patient serum
- Human RBCs are added to streptolysin O and serum mix
- Antistreptolysin Antibody will neutralize the streptolysin and prevent Hemolysis
- Maximal serum dilution that still prevents Hemolysis will result in an ASO Titer
IV. Resources
- Plaque Reduction Neutralization Test (Wikipedia)
V. References
- Goldberg (2014) Clinical Physiology, Medmaster, Miami, p. 83-5