Agglutination Methods

Question 1

The process by which particulate antigens, such as cells, aggregate to form large complexes when the specific antibody is present.

Answer 1

Direct Agglutination

Question 2

Types of Direct Agglutination

Answer 2

Direct Bacterial Agglutination & Latex Agglutination

Question 3

Antibodies + surface antigens of bacteria in suspension → visible agglutination

Answer 3

Direct Bacterial Agglutination

Question 4

When an antigen (e.g., C-reactive protein) is present in the test specimen, it binds to the antibody sites on the latex bead surface. This interaction forms visible cross-linked aggregates of latex beads and the antigen.

Answer 4

Latex Agglutination

Question 5

Latex Agglutination - Immunologic Assays:

Answer 5

○ C-reactive protein
○ IgG rheumatoid factors
○ IgM rheumatoid factors
○ Rubella antibody

Question 6

Examples of Direct Agglutination

Answer 6

Febrile agglutinins
Salmonella
Shigella serotyping

Question 7

An antigen-antibody reaction that results in the clumping of red blood cells

Answer 7

(Direct) Hemagglutination

Question 8

Examples of (Direct) Hemagglutination

Answer 8

ABO Typing

Question 9

A reaction in which soluble antigens are bound to
latex beads, bentonite, or charcoal → the particles are agglutinated by the corresponding antibody.

Answer 9

Passive Agglutination

Question 10

Examples of Passive Agglutination

Answer 10

Rheumatoid Factor

Question 11

A reaction in which soluble antigens are adsorbed onto RBCs (i.e., proteins coupled to RBCs using bis- diazotized benzidine) → RBCs are agglutinated by the corresponding antibody.

Answer 11

Passive Hemeagglutination

Question 12

Examples of Passive Hemeagglutination

Answer 12

Cold agglutinins

Question 13

A reaction in which carrier particles coated with antibody clump together due to combination with antigen.

Answer 13

Reverse Passive agglutination

Question 14

Examples of Reverse Passive agglutination

Answer 14

Rapid tests for identification of bacteria

Question 15

An agglutination reaction based on competition between the particulate antigen (reagent) and soluble antigen (specimen) for limited sites on a reagent antibody.

Answer 15

Agglutination Inhibition

Question 16

Examples of Agglutination Inhibition

Answer 16

Detection of illicit drugs

Question 17

A test for detecting antibodies to certain viruses that agglutinate RBCs (in the presence of antibody, the virus is neutralized, and hemagglutination does not occur).

Answer 17

Hemeagglutination inhibition

Question 18

Examples of Hemeagglutination inhibition

Answer 18

Rubella antibody

Question 19

An agglutination reaction in which bacteria are used as the carrier for the antibody.

Answer 19

Coagglutination

Question 20

Examples of Coagglutination

Answer 20

Rapid tests for the identification of bacteria

Question 21

Detection of non-agglutinating antibody by coupling with 2nd antibody (antihuman globulin [AHG])

Answer 21

Antiglobulin- mediated agglutination (Coomb’s test)

Question 22

Examples of Antiglobulin- mediated agglutination

Answer 22

Direct and indirect antiglobulin test

Question 23

demonstrate in vivo attachment of antibody or complement to an individual’s red blood cells.

Answer 23

Direct Antiglobulin Test/ Direct Coomb’s Test

Question 24

determine the presence of a particular antibody in a patient, or it can be used to type patient red blood cells for specific blood group antigens. (In vitro)

Answer 24

Indirect antiglobulin test / Indirect Coombs’ test

Question 25

Antigens or antibodies are attached or immobilized onto a solid support (e.g., gel particles, plastic beads, microtiter wells) to create a solid phase.

Answer 25

Solid Phase Particle Agglutination

Question 26

used for detecting antibody, antiviral antibody is chemically bound to erythrocytes.

Separately, the serum specimen and virus antigen are mixed, to which is added the antibody-sensitized erythrocyte suspension.

Answer 26

Reverse Passive Hemagglutination Test (RPH)