Agglutination

Question 1

• It provides flexible and useful method for semi quantitating of either antigen or antibody concentration.

Answer 1

Agglutination test

Question 2

• It is one of important laboratory method to detect antigen antibody reaction.

Answer 2

Agglutination test

Question 3

• The reaction occurs between insoluble antigen and appropriate antibody.

Answer 3

Agglutination

Question 4

Agglutination
• The reaction will results in forming…

• Antibodies that produce such reactions are called…

Answer 4

aggregate or agglutinate

agglutinins

Question 5

Stages of agglutination reaction

Answer 5

Primary phage- Sensitization

Secondary phase- Lattice formation

Question 6

• Antibody reacts with single antigenic determinants on or close to particle surface
• It is a rapid and reversible reaction.
• Based on Law of Mass Action

Answer 6

Primary phage- Sensitization

Question 7

• A single antibody molecule binds to antigenic determinants on adjacent particles.

• The visible reaction occur under appropriate conditions and over time, particles remain connected and interconnected by antibody bridge.

Answer 7

Secondary phase- Lattice formation

Question 8

•_____ is 700 times more efficient in agglutination than____ (Restricted hinge region of IgG than IgM)

Answer 8

IgM

IgG

Question 9

An excess of antibody inhibits precipitation reactions, such excess can also inhibit agglutination reactions; this inhibition is called the…

Answer 9

prozone effect

Question 10

combination of an insoluble particulate antigen with its soluble antibody

• forms antigen-antibody complex
• particles clump/agglutinate
  • used for antigen detection

Answer 10

Active/Direct agglutination test

Question 11

Examples
> The particle antigen may be a bacterium. e.g.: Serotyping of E. coli, Salmon using a specific antiserum.
The particle antigen may be a parasite. e.g.: Serodiagnosis of Toxoplasmos The particle antigen may be a red blood cell. e.g.: Determination of blood group

Answer 11

Direct agglutination

Question 12

• Converting a precipitating test to an agglutinating test

• Chemically link soluble antigen to inert particles such as LATEX carbon, gelatin, silicates or RBCs.

Answer 12

Passive Agglutination Test

Question 13

• Particle size- 7um to 0.8um
• Addition of specific antibody will cause the particles to agglutinate

Answer 13

Passive Agglutination Test

Question 14

• Examples: RA factor, antinuclear antibodies (ANA) - detects autoimmnity, ASO, Spirochete antibody(TPHA).

Answer 14

Passive agglutination

Question 15

E.g. Rose waaler test -detects rheumatoid arthritis

• RA factor in rheumatoid arthritis patients acts as antibody to human gamma globulin.
• It can agglutinate red cells coated with globulins

• Antigen is sheep RBCs suspension sensitized with rabbit anti sheep erythrocytes antibody (amboreceptor).

Answer 15

Hemeagglutination

Question 16

: latex particles used as carrier molecules

Eg: antigen coated latex particles are used in detection of ASO, S.agalactiae, Clostridium difficile toxins A and B, rotavirus

Antibody coated latex particles are used in detection of CRP, RA factor, HCG.

Answer 16

Latex agglutination

Question 17

• Used for syphillis
• Carbon is the carrier particle
• Cardiolipin antigen is coated with charcoal (carbon)
• Detect reagin - an antibody like substance in the plasma of syphillis

Answer 17

RPR or rapid plasma reagin

Question 18

• Antibody is attached to the particulate carrier. One of the most commonly used laboratory tests that involves latex particle agglutination is the procedure for C-Reactive Protein (CRP).

Answer 18

Reverse Passive Agglutination test

Question 19

: antibody linked to LATEX e.g. Lancefield grouping in Streptococci

Answer 19

• Reverse PAT

Question 20

• When a particulate antigen is mixed with its antibody in the presence of electolytes at a suitable temperature and pH, the particles are clumped or agglutinated

Answer 20

Agglutination reaction

Question 21

CRP

Antibody or Antigen?

Answer 21

Antigen