450_Chapter 10: Agglutination Methods

Front 1

Explain the difference between agglutination and precipitation

Back 1

Precipitation: Ab binding to an soluble Ag
Agglutination: Ab binding to insoluble Ag

Front 2

Discuss the principles of agglutination

Back 2

Formation of immune complex with:
- Cells or latex particles
-Uses: drug and hormone assays, infectious disease
Mechanism of agglutination:
-Sensitization: physical attachment of Ag to Ab
-- Reversible, rapid
-- Affected by Ag-Ab ratio and physical conditions (pH, temp, time...)
- Lattice formation - cross-linking between sensitized particles
--Slower than sensitization phase

Front 3

Explain the principles of pro-zones, post-zone, zone of equivalence and how it can affects the results of an agglutination assay. Explain how to avoid pro- zone reactions

Back 3

Prozones:Ab excess, which can result in a false-negative reaction. serial dilution is used to avoid this problem
Zone of equivalence: optimum concentration
Postzone: Ag excess, no lattice formation

Front 4

The quality of test results in an agglutination reaction depends on:

Back 4

- Duration of incubation
- Amount of Ag conjugated to the carrier
- Avidity of Ag conjugated to the carrier

Front 5

Flocculation procedures differ from latex agglutination procedures because

Back 5

Soluble antigen reacts with Ab

Front 6

In the hemagglutination technique, antihuman globulin is used as an enhancement medium to detect ___

Back 6

IgG

Front 7

The prozone phenomenon can result in a

Back 7

False negative reaction

Front 8

The effect of competing Ab seeking to attach to Ag site is called

Back 8

Steric hindrance

Front 9

All the following are methods that can be used to enhance the agglutination of IgG Ab:

Back 9

- Centrifugation
- Treatment with proteolytic enzymes
- Using colloids

Front 10

A classic technique for the detection of viral Ab is:

Back 10

Indirect hemagglutination

Front 11

Precipitation

Back 11

Aggregation of soluble test Ag

Front 12

Agglutination

Back 12

Aggregation of particulate test Ag

Front 13

Coagglutination

Back 13

Uses Ab bound to a particle to enhance visibility of agglutination

Front 14

Flocculation

Back 14

Based on the interaction of soluble Ag wit hAb, resulting in formation of a precipitate of fine particles

Front 15

Hemagglutination

Back 15

Agglutination of erythrocytes in tests for Ab detection

Front 16

Sensitization:

Back 16

the first phase of agglutination
Represents the physical attachment of Ab molecules to Ag on the RBC membrane

Front 17

Agglutination can be used to enhance reactions by all the following means:

Back 17

Decreasing ionic strength of the reaction
Centrifugation
Using colloids and antihuman globulin