Module 12: Immunological Testing Methods Obj. 3 SA

Question 1

Agglutination

Answer 1

formation of cross linked Ag-Ab lattices in which Ag is on the surface of a cell or other insoluble particle

Question 2

3 major agglutination reactions

Answer 2

direct
indirect (passive)
Viral

Question 3

Direct agglutination

Answer 3

for naturally occurring Ag on surface of a cell
ex. Anti A antisera attaches to A Ag on RBC

ex. Mycoplasma pneumoniae Ab attaches to I antigen on RBC
ex. Heterophile Ab produced during infection mononucleosis will agglutinate sheep red cells

Question 4

Indirect (Passive) Agglutination

Answer 4

Ag is actively (by manufacturer) attached to the carrier particle (charcoal, latex, gelatine, sheep rbc)

Ex. Serological producers to diagnose syphilis
ex. Rubella testing, Rheumatoid arthritis may produce an Ab called RF; Anti-streptolysin O is an antibody produced by patients post infection with beta hemolytic group A Strep.; Detect CRP using latex particles with anti-CRP attached

Question 5

Viral hemagglutination Inhibition

Answer 5

indirect way to detect presence of viral Ab in patient
POS REACTION:
Viral reagent + pt sample WITH Ab + REAGENT RBC = NO agglutination

NEG REACTION:
viral reagent + pt sample W/O Ab + reagent RBC = Agglutination