Clinical Immunology Flashcards
Papain or Pepsin:
Breaks Ab into two individual arms; cannot cross link
Papain
Papain or Pepsin:
Can still look at antibody immunoprecipitation
Pepsin
Term for the antibody:antigen ratio where there is optimal binding and cross-linking
Equivalence
Effect when there is too much antibody and precipitation does not occur
Prozone effect
Results in false negative
This technique demonstrates the diffusion of antigen from its site of inoculation within a gel matrix that contains antibody
At the point of equivalence, a precipitin line develops
A standard curve can be used to quantitate antigen or antibody concentration within an unknown solution
Radial immunodiffusion (RID)
What do you learn from a radial immunodiffusion?
Quantitate antigen or antibody concentration within an unknown solution
Involves the inoculation of serum from a patient and serum from a normal control onto a gel matrix poured onto a glass slide
The slide is exposed to an electric field, and the proteins migrate based on their charge
After the electrophoresis is complete, anti-sera specific for all human antibody isotypes is inoculated into a trough set up between the 2 sera samples
Immunoelectrophoresis
Tests that are commonly used to rapidly diagnose pneumococcus and meningococcus infections and identify the specific strain of the isolate
These tests use antibodies bound to latex beads
When a sample (CSF, blood, etc.) is added that contains the antigen, the antibodies and beads are cross-linked and settle out of solution
These tests are rapid and relatively easy to perform
Agglutination tests
Blood typing involves this type of test
Agglutination
Agglutination can be observed in blood typing assays due to the fact that antibodies of this isotype can be used
IgM
Direct or indirect Coombs test:
performed to determine whether maternal antibodies have bound fetal RBCs
Direct
Direct or indirect Coombs test:
performed to determine whether maternal serum contains antibody against Rh antigen
Indirect
Both direct and indirect Coombs tests requires these
Antibodies against human antibodies to agglutinate the RBCs
Anti-D antigen sera that is administered to Rh- mothers carrying a potentially Rh+ fetus
Rhogam
Difference between radioimmunoassay and ELISA
RIA uses a radioactive label
ELISA uses an enzyme label
What can you learn from an ELISA?
Can be used to detect either antigen or antibody within a sample of interest
Technique that Involves the disruption of the virus and SDS-PAGE
The proteins are transferred to a nitrocellulose membrane that can be probed with antibody (patient sera)
Can determine the size of the protein(s) that the serum Abs recognize
Western blot
What can you learn from a western blot?
The size of the protein(s) that the serum antibodies recognize
(which is not possible with ELISA)
Control antibodies used in pregnancy tests
Enzyme-conjugated antibodies against murine antibodies
WBCs can be separated out of whole blood using this
a Ficoll density gradient
Cells that can be separated out of whole blood using a Ficoll density gradient
WBCs
What can you learn from flow cytometry?
Can differentiate cells that look similar microscopically, but differ in the proteins expressed on their surface (e.g. CD4 vs CD8 T cells)
These stimulate lymphocytes in a manner that does not take into account the antigen the cells specifically recognize, and can be used to identify global deficiencies in B or T cell populations
Mitogens
What can mitogens be used for?
Identifying global deficiencies in B or T cell populations
What can you learn from a limiting dilution assay?
The number of cells within a host that respond to a specific stimuli
What do you learn from an ELISpot?
The number of cytokine-producing cells within the population
