20.1 Flashcards
antibody specificty
regions of the antibody that have unique patterns of amino acids that can only bind to target antigens with a molecular sequence.
cross-reactivity
antibodies raised against one antigen bind to a chemically similar but different antigen.
affinity
a measure of the binding strength between an antibody binding site and an epitope
avidity
the total strength of all the interactions in an antibody-antigen complex.
antiserum
serum collected from an animal following eposure to an antigen.
second injection
will activate memory cells that make class IgG antibodies against the antigen
affinity maturation
results in a pool of antibodies with higher average affinity. occurs because of mutations in the immunoglobulin gene variable regions, resulting in B cells with slightly altered antigen binding sites.
adjuvant
a chemical that provokes a generalized activation of the immune system that stimulates greater antibody production, is mixed with the antigen
polyclonal antisera
used in clinical tests to determine if a patient is producing antibodies in response to a particular pathogen. indirect means of determining if a pathogen is present.
false-positive
a test that confirms the presence of an antigen that is not there
false-negative
a test that confirms that no antibodies are prsent
test sensitivity
the probability of getting a positive test result when the patient is infected
test specificity
the probability of getting a negative test result when the patient is not infected.
monoclonal antibodies
high specificity that can be attained by binding antibodies with high affinity to a single epitope. can be produced by immunizing an animal multiples times with a specific antigen.
hybridoma cells
myeloma (cancerous b cells) fused with normal B cells.
humanized monoclonal antibodies
genetically altered antibodies.
plantibodies
genetically engineered plants
precipitin
visible antigen-antibody complex
precipitin ring test
used to determine the relative amount of antigen-specific antibody in a sample of serum.
titer
the highest dilution with a visible ring. the reciprocal of the highest dilution showing a positive result is expressed as a whole number
double immunodiffusion or Ouchterlony assay
holes punched into agar to form cells. then antigen and antisera are added, proteins diffuse and the precipitin arcs form in the agar. Determines if an antiserum has antibodies against a particular antigen.
radial immunidiffusion
quantify antigen concentration rather than compare different antigens.
flocculant assay
flocculation (foaming) is observed in the test tube fluid
neutralization assay
when antiviral antibodies neutralize infections by coating the virions and blocking the binding
