7. Opsinization: the process by which antibody
binding to both antigen and phagocyte enhances
phagocytosis
http://podcast.scischina.org/groups/drmarkham/public/cd01e.jpg
8. *Ab acts as an opsin and makes the bacterium tastier
for the phagocyte AND clumps bacteria together
allowing the phagocyte to engulf many at once
9. Importance of measuring Ab-Ag
interactions:
•Quantifying Ab
•Identifying Ab targets
•Ab specificity for many targets
• Identification
• Quantification
10. Applications of Ab-Ag interactions:
•ELISAs
•Immunoflorescence
•immunodiffusion
•Immunoprecipitation
•flow cytometry
•Western blots
•magnetic bead column separation
11. Simple Slide: Qualitative (visual)
confirmation of the specificity of an
antiserum to the agglutinated particles.
Example: Blood typing
12. Quantitative determination of the amount
of antibody in the serum (titer)
No
Agglutination
Agglutination
http://nfs.unipv.it/nfs/minf/dispense/immunology/blt.jpg
13. Titer: How far you can dilute the patient’s
serum and still have it contain enough
antibodies to yield a detectable Ab-Ag
interaction.
*Higher titer means higher starting concentration of
Serum/Ab
14. Using agglutination to track disease progression:
What is the titer for this patient?
*Dilute the serum, add a constant amount of antigen- You want
to know how far you can dilute the patient’s serum (titer) and
still have agglutination to determine the concentration of
antibody in the original sample
16. For today:
Sheep Red Blood Cell = SRBC = Ag
Anti-SRBC antiserum = Ab against
SRBC (rabbit)
17. Add PBS
to wells Add Ab to
1A-12A well 1A
Perform serial
dilution from
well 1A-11A
Add Ag to
wells
1A-12A
*Pipet up and down at least 3 times during serial dilution
*Change tip between each serially dilution
*Avoid contaminating the Ag stock with Ab!
Hinweis der Redaktion
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Ab= anti-SRBC, Ag=SRBC, Step 1= binding of Ab to Ag. Step 2= crosslinking of Ab with 2 Ag to form large aggregates\n
