Lab Exam #2

Front 1

what is the fundamental reaction of immunology?

Back 1

Ab+Ag > Ab-Ag

Front 2

What makes it possible to perform qualitative and quantitative assays on the Ag-Ab system?

Back 2

Macromolecular antigens and antibodies frequently form compleses that become insoluble and precipitate from solution.

Front 3

Precipitation occurs?

Back 3

Because each Ab can bind to more than one Ag and each macromolecular Ag can be bound by more than one Ab.

Front 4

Experimentally?

Back 4

Ag is added to a constant amount of Ab in solution

Front 5

Antibody-excess zone?

Back 5

Initially, the amount of the Ab in solution is much greater than the amount of Ag in solution. Ab>Ag.

Front 6

Equivalence zone, or equivalence point?

Back 6

As more An is added, the amount of protein precipitated increases until the antigen and antibody molecules are at an optimal ratio (roughly equal proportions). Ab=Ag.
Where maximum precipitation occurs.

Front 7

Antigen-excess zone?

Back 7

When the amount of Ag in solution exceeds the amount of Ab, the amount of precipitation. Ag>Ab

Front 8

When Ab and Ag are inserted into diff. areas of an agarose gel?

Back 8

They diffuse toward each other and form opaque bands of precipitate at the interface of their diffusion fronts

Front 9

Precipitation reactions of Ab and Ag in agarose gells provide?

Back 9

A method of analyzing the various Ab-Ag reactions in a system.

Front 10

Ouchterlony?

Back 10

Double diffusion in two dimensions

Front 11

Reactants?

Back 11

Diffuse from the wells toward each other >> precipitate where they meet at equivalent proportions.

Front 12

A single Ag will combine w/ ?

Back 12

its homologous Ab to form a single precipitation line.

Front 13

When two Ag are present?

Back 13

Each behaves independently of each other.

Front 14

The number of precipitin bands indicates?

Back 14

There are at least that many Ab-Ag systems present.

Front 15

Double diffusion in 2-D is a useful technique for?

Back 15

Comparing Ag for the number of identical or cross-reacting determinants.

Front 16

Reaction of Identity?

Back 16

A soln of Ag is placed in 2 adjacent wells and the homologous Ab is placed in the center well, the 2 precipitin bands that form will join at their closest ends and fuse.

Front 17

Reaction of non-identity?

Back 17

When unrelated Ag’s are placed in adjacent wells and the center well is filled w/ Ab for each Ag. The precipitin bands will form independently of each other & will cross.

Front 18

When will the precipitin lines fuse?

Back 18

When the Ag in one well & the antiserum in the center well = homologous pair.
And the Ag in an adjacent well is a cross-reacting Ag.

Front 19

Partial identity?

Back 19

When the precipitin lines fuse an additional spur occurs projecting towards the cross-reacting antigen.

Front 20

The spur projects towards?

Back 20

The Ag with the fewer determinants (i.e. cross-reacting Ag).

Front 21

The spur represents?

Back 21

The reaction b/t homologous Ag and those Ab molecules that do not combine with the cross reacting Ag.
Homologous Ag contains determinants (recognized by hom. Ab) which are NOT present on x-reacting Ag.

Front 22

Why is the spur usually less dense than the precipitin ban from which it projects?

Back 22

Non-cross-reacting antibodies often compose only a fraction of the total antibody involved in the homologous precipitin reaction.

Front 23

Ab-Ag interactions are usful in the ?

Back 23

Defense of the body against bacterial and viral infections and toxins.

Front 24

The defense capabilities are dependent upon?

Back 24

The recognition of Ag by humoral components of the immune system.
Specific Ab are then produced in response to exposure to the Ag.

Front 25

The formation of Ag-Ab complexes is the first step in?

Back 25

Removing infectious agents from the body.

Front 26

Because each Ab can bind more than one Ag and each Ag can be bound by more than one Ab?

Back 26

Very large macromolecular complexes can form

Front 27

Very large macromolecular compleses form?

Back 27

Precipitates which can be cleared from the body through various themes.

Front 28

These precipitates are also useful for?

Back 28

Laboratory and diagnostic tests.

Front 29

Precipitation reactions of Ab and Ag in agarose gells provide ?

Back 29

A method of analyzing the various Ab-An reactions in a system.

Front 30

Ouchterlony?

Back 30

A single Ag will combine with its homologous Ab to form a single precipitation line.

Front 31

Radial Immunodiffusion (RID)?

Back 31

Is a technique that can quantitatively determine the concentration of an Ag.

Front 32

RID is used for?

Back 32

Sensitive quantitative technique that is often used clinically to detect patient levels of blood proteins.

Front 33

Agarose contains?

Back 33

Ab is incorporated into molten agarose > gel

Front 34

Small well?

Back 34

Are filled with known concentrations of Ag which corr. To the Ab in the agarose.
Samples of unknown concentrations are pplaced in similar wells.

Front 35

The antigen soln?

Back 35

Diffuse outwards from the well in a circular pattern surrounding the well.

Front 36

Antibody?

Back 36

Is present in excess & diffusion of the Ag will continue until a stable ring of Ag-Ab precipitate forms.

Front 37

There are Ag-Ab complexes?

Back 37

Throughout the zone surrounding the well w/in the precipitin line.

Front 38

Equivalence zone or equivalence point?

Back 38

At the precipitin line is where the greatest # of complexes can be found
b/c the Ag and Ab are present in roughly equal proportions.

Front 39

How long does it take?

Back 39

24 to 48 hours for optimal diffusion to occur and precipitation to b/c apparent.

Front 40

For each antigen?

Back 40

An endpoint precipitation ring of a certain D will form

Front 41

From the known standard concentrations?

Back 41

A standard curve can be drawn by plotting Ag concentration versus the D^2 measurements of the rings.

Front 42

From the linear calibration curve?

Back 42

The concentration of the unknown samples may be determined.