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

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

? 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

Bacterial agglutination ?

Bacterial agglutination no agglutination ?

? 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

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

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

? 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 ?

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

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

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

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 ?

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

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

Immunoprecipitation

Reaction of nonidentity Immunoprecipitation Reaction of identity Reaction of nonidentity