Is 2

• What is the Zone of Equivalence in immunology?


  Optimum precipitation occurs
• What happens in the Prozone phenomenon?

  Antibody excess leads to false negatives
• How can the Prozone phenomenon be remedied?

  Dilute the antibody
• What occurs when antigen combines with only one or two antibody molecules?

  No cross-linkages are formed
• What is indicated by tube Nos. 5-7 showing a stronger reaction than tube Nos. 3-4?

  Antibody concentration is optimal
• What does the Post zone phenomenon indicate?

  Antigen excess leads to false negatives
• How can the Post zone phenomenon be remedied?

  Add more specimen
• What does turbidimetry measure?

  Light scattered by a solution
• What does nephelometry measure?

  Light at a particular angle
• What is measured in endpoint assays?

  Measurements after reagent is added
• What does the kinetic/rate method measure?

  Rate of scatter after reagent is added
• What factors affect passive immunodiffusion?

  • Size of particles
  • Temperature
  • Gel viscosity
  • Hydration
• What is Radial Immunodiffusion (RID)?

  Single diffusion, single dimension technique
• What is the major drawback of the Mancini method?

  Requires 24 to 72 hours for results
• What occurs when equivalence is reached in the Mancini method?

  No further change in ring diameter
• What does the Fahey and McKelvey method measure?

  Diameter log of concentration
• What immunoglobulins can be measured using these methods?

  IgG, IgM, IgA, and complement components
• What is Ouchterlony technique?

  Classic double diffusion immunochemical technique
• How do antigens and antibodies behave in Ouchterlony technique?

  Diffuse independently through a medium
• What does the endpoint in Ouchterlony indicate?

  Precipitin line density equals concentration
• What are the patterns observed in serological reactions?

  1. Identity: Common epitope - dot line
  2. Non-identity: No common epitope - crossed lines
  3. Partial identity: Fusion of lines with spur
• What are some applications of serological techniques?

  Detect fungal antigens and autoimmune diseases
• What is the purpose of electrophoretic techniques?

  • Speed up separation
  • Separate based on electric charge
• What is Rocket immunoelectrophoresis?

  One-dimensional electroimmunodiffusion technique
• What does the height of the precipitin line indicate in Rocket immunoelectrophoresis?

  Increases with higher antigen concentration
• What is the process of immunoelectrophoresis?

  Electrophoresis followed by diffusion
• What is the end result of immunoelectrophoresis?

  Bowing or thickening of bands
• What are some uses of immunoelectrophoresis?

  Differentiation of immunoglobulin classes
• What is the most common application of immunoelectrophoresis?

  Diagnosis of monoclonal gammopathy
• What is the purpose of immunofixation electrophoresis (IFE)?


  Faster and easier interpretation of results
• What is the role of antisera in IFE?

  Fixed on gel's surface
• What is the significance of the sixth lane in IFE?

  Normal lane for serum proteins
• How does polyclonal hypergammaglobulinemia appear in IFE?

  Faint staining bands
• How does monoclonal hypergammaglobulinemia appear in IFE?

  Local staining bands in gamma region
• What is the principle of countercurrent immunoelectrophoresis?

  Antigen and antibody added opposite each other
• Who published the first report on agglutination?

  Gruber and Durham
• What is the two-step process in agglutination?

  Sensitization followed by lattice formation
• What enhances lattice formation in agglutination?

  Low ionic strength saline and albumins
• What is the role of enzymes in agglutination?

  Neutralize surface charge on red blood cells
• What is the best temperature for IgG agglutination?

  30°C to 37°C