1. Agglutination Tests
Lattice Formation

2. Agglutination/Hemagglutination
Definition - tests that have as their endpoint the agglutination of a particulate antigen
Agglutinin/hemagglutinin Y + 
Qualitative agglutination test
Ag or Ab

3. Agglutination/Hemagglutination
Quantitative agglutination test
Titer
Prozone
1/2
1/4
1/8
1/16
1/32
1/64
1/128
1/256
1/512
1/1024
Pos.
Neg.
Titer 64 8
512
<2 32
128 4
Patient 1 2 3 5 6 7

4. Agglutination/Hemagglutination
Definition
Qualitative test
Quantitative test
1/2
1/4
1/8
1/16
1/32
1/64
1/128
1/256
1/512
Applications
Blood typing
Bacterial infections
Fourfold rise in titer
Practical considerations
Easy
Semi-quantitative

5. Passive Agglutination/Hemagglutination
Definition - agglutination test done with a soluble antigen coated onto a particle Y + 
Applications
Measurement of antibodies to soluble antigens

6. Coombs (Antiglobulin)Tests
Incomplete Ab
Direct Coombs Test
Detects antibodies on erythrocytes +  Y
Patient’s RBCs
Coombs Reagent
(Antiglobulin)

7. Coombs (Antiglobulin)Tests
Indirect Coombs Test
Detects anti-erythrocyte antibodies in serum Y
Patient’s
Serum
Target
RBCs + 
Step 1 +  Y
Coombs Reagent
(Antiglobulin)
Step 2

8. Coombs (Antiglobulin)Tests
Applications
Detection of anti-Rh Ab
Autoimmune hemolytic anemia

9. Agglutination/Hemagglutination Inhibition
Definition - test based on the inhibition of agglutination due to competition with a soluble Ag Y + 
Prior to Test Y + 
Test
Patient’s sample

10. Agglutination/Hemagglutination Inhibition
Definition
Applications
Measurement of soluble Ag
Practical considerations
Same as agglutination test