Antigen-antibody Reactions

The inverse of the highest dilution of a substance eliciting a demonstrable reaction with a given amount of target substance

Serum that contains antibodies produced by natural infection or repeated innoculations of antigen

The portion of the serum protien containing antibody reactivity against an antigen

An antibody which reacts with a SOLUBLE anitigen resulting in a detectable insoluble precipitate

An antibody which reacts with an INSOLUBLE antigen resulting in agglutination. These are primarily IgM.

An anitbody which brings about lysis of red blood cells. IgM is more efficient than IgG.. complement is required.

Either the antigen or antibody

IgM levels are used to detect current infection. IgG can be used to diagnose current or past infection.

One sample is taken while the person is sick and another is taken after the person is healthy again and compared. a titer 4 fold increase is indicative of disease.

Sensitivity test is most helpful because negative results can be ruled out (can have false positives). specificity is most helpful when the result is positive to rule it in (can create false negatives).

Affinity is the sum of intrinsic attractive and repulsive forces (implies a univalent antigen). avidity is the overall strength of binding between a multivalent antigen and antibody.

Affinity, avidity, pH, temp, ionic strength of rxn buffer, cross-rxns

Means antigens with similar epitopes can bind to the same antibody. this can create false positives. this is why ELISA's (very cheap) are used to screen large populations for HIV and the positives are run through a western blot to ensure that they are infact true positives.

Usually to test for an anitgen and is clinically used to test for rabies and herpes.

Is usually used to test for antibodies but can be used to detect antibodies. this is clincally used to diagnose syphilis. (primary binding test)