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Question 1

Negative agglutination:

Answer 1

• Solid “button” sediment with turbid supernatant

Question 2

Name two types of haemagglutination tests

Answer 2

• Direct haemagglutination: detect antibodies against red cell determinants - Passive haemag.: …against compounds artificially coupled to red cells

Question 3

The essential differences between agglutination and precipitation are in:

Answer 3

• size, solubility and location of the antigen - in agglutination the antigens are whole cells, like red cells but in precipitation the antigen is a soluble molecule

Question 4

Radial immunodiffuion (RID)

Answer 4

is quantitative method used for quantification

Question 5

Immunoelectrophoresis (IEF)

Answer 5

precipitation reaction, in which direct current is used to regulate the movement of antigen and antibody molecules in agar or agarosis gel

Question 6

Seperation of proteins in electric field depends on:

Answer 6

• Whole electric charge - Molecular mass - Isoelectric point

Question 7

Serum proteins separate into six major fractions according to their charge at given pH

Answer 7

• α1-globulins, α2-globulins, β-globulins, γ-globulins, hydragel protein K20, hydragel proteins (E)

Question 8

What does ELISA stand for?

Answer 8

• Enzyme-Linked ImmunoSorbent Assay - Result: soluble colour product

Question 9

Application of EIA can be used for:

Answer 9

• Qualitative detection of the presence of Ab or Ag - Quantitative determination concentration of Ab or Ag

Question 10

Advantage of EIA:

Answer 10

• Detection of Ag of pathogens directly - Detection of Ab against many bacterial, viral or parasitic agents - Very flexible method
  Disadvantage: false positive results

Question 11

ELISA techniques are divided to what two groups?

Answer 11

• For detection of antigens: sandwich ELISA & competitive ELISA - For detection of antibodies: direct ELISA & blocking ELISA

Question 12

Name two different types of IFA

Answer 12

• Direct immunofluorescence staining - the primary Ab is labelled with fluorescence dye - Indirect immunofluorescence staining - secondary reagent (antiglobulin or protein A/G labelled with fluorophore) is used to recognize a primary Ab - Advantages: identification of antigenic structures, identif. of different antigens in one sample, identif. of the live and dead bacteria in one sample, rapid method
• Disadvantages: requirement of expensive equipment and reagents and trained personnel Green fluorescence - live cells Red fluorescence - dead cells