1. Introduction to Lab Ex. 22: Immunology I
- Bacterial Agglutination
- Immunoprecipitation

2. Introduction to Lab Ex. 22: Immunology I – Bacterial Agglutination
- Immunoprecipitation
Immune responses include all the activities of the immune system
toward maintaining the healthy status of the host.
These would include protecting against pathogens – foreign antigens
Specific Immune responses are one of two kinds:
Antibody-mediated
Cell-mediated
Antibodies are proteins secreted by specific immune cells to counteract
and rid the antigens (and thus the pathogens they may be associated with)
Antibodies are specific for the antigen that trigger their formation.
Depending on the nature of the antigen the antigen-antibody reactions
result in different reactions, ex. Agglutination or precipitation

3. ? agglutination no agglutination
 BACTERIAL AGGLUTINATION
. is the reaction between a particulate antigen and its specific antibodies
Antibody specificity known (S. enteriditis)
Salmonella species identity not known (?)
Agglutinationreaction between antibody and particulate antigen ?
agglutination
no agglutination
Table 1. Serological classification of some common Salmonella species.
Salmonella species Serological group
S. typhimurium B
S. paratyphi C C1
S. enteriditis D
S. anatum E

4. Bacterial agglutination?

5. Bacterial agglutination
no agglutination ?

6. ? agglutination no agglutination Bacterial agglutination
Antibody specificity known (S. aureus)- antigen on the surface of bacteria
Staphylococcus species identity not known (?)
S. aureus
S. epidermidis ?
agglutination
no agglutination

7. ? agglutination no agglutination Bacterial agglutination S. aureus
S. epidermidis ?

8. Latex beads
(dyed blue)
S. epidermidis
S. aureus
S. aureus-specific
antibodies

9. ? Note: these latex beads are dyed red agglutination no agglutination
Bacterial agglutination
Note: these latex
beads are dyed red
agglutination
no agglutination
S. aureus
S. epidermidis ?

10. Mark your bacterial agglutination cards
Bacterial agglutination (new procedure). #1
Mark your bacterial agglutination cards
S. aureus
S. epidermidis

11. Mix the latex agglutination reagent dropper bottle
Bacterial agglutination #2
Mix the latex agglutination reagent dropper bottle
and dispense one drop onto each circle
S. aureus
S. epidermidis

12. Bacterial agglutination#3
Using a sterile toothpick , pick up and smear 1 suspect colony from your negative control in the proper ring. #4
Using a NEW sterile toothpick , pick up and smear 1 suspect colony from your positive control in the proper ring. #5
Using a NEW sterile toothpick , pick up and smear 1 suspect colony from your unknown in the proper ring.
S. aureus
S. epidermidis

13. Bacterial agglutination (Part B).#6
Pick up and gently rock the card for 20 seconds and observe for agglutination under normal lighting conditions
S. aureus
S. epidermidis ?

14. Immunoprecipitation
- is the reaction between a soluble antigen and its specific antibodies
soluble antigens are smaller and in solution; complexing with antibodies make these
bigger and they fall out of solution as a precipitate –visible to the eye.
Antibody specificity known (toxin, protein, etc.)
Antigen presence or identity not known (?)
Precipitationreaction between antibody and soluble antigen

15. Immunoprecipitation Antibody specificity known (toxin, protein, etc.)
Antigen presence or identity not known (?)
Precipitationreaction between antibody and soluble antigen

16. Immunoprecipitation

17. Reaction of nonidentity
Immunoprecipitation
Reaction of
identity
Reaction of nonidentity