Page 156 - MNU microbiology theoritical 2025

General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025

b) Quantitative agglutination test

Agglutination tests can also be used to quantitate the level of antibodies to

particulate antigens.

Titer

Different dilutions of serum are tested with a constant amount of antigen and

greatest dilution for antigen antibody interaction is the measure or Titer

B- Precipitation tests

Antibody + soluble Ags = precipitate Antigen and antibody are placed on
a slide and mixed by shaking

In a positive test floccule

• Ring test • Tube test

• Slide test • Immunodiffusion

1- Ring test

• Solution of antibody is carefully layered on top of a solution of antigen, no

mixing between the two.

General Microbiology & Immunology (PM 401) theoretical handbook Page 145