2. • What is passive agglutination?
• What are various types of passive agglutination tests?
AREAS OF INTERESTS…
3. LET’S GET STARTED…
What is agglutination?
Particulate antigen + its
specific antibody
Electrolytes at an optimal
temperature and pH
Visible clumping of particles
4. LET’S GET STARTED…
What is precipitation
reaction?
Soluble antigen + its specific
antibody
Electrolytes at an optimal
temperature and pH
Insoluble precipitate
5. LET’S GET STARTED…
And what is Passive
Agglutination??
Precipitation reaction
Agglutination tests
By attaching soluble antigens to
the surface of carrier particles
such as latex particles, bentonite,
RBCs, etc.
6. ADVANTAGES OF PASSIVE AGGLUTINATION
Advantage of Passive agglutination over
precipitation tests are:
• More convenient
• More sensitive for detection of
antibodies
• More sensitive for detection of antigens
(Reverse passive)
7. REVERSE IS POSSIBLE…
When instead of antigen, the antibody is
adsorbed on the carrier particles for
estimation of antigens, it is known as
Reverse passive agglutination
9. Simplifying the course of study...
Passive
agglutination
Coagglutination
test
Latex
agglutination test
Hemagglutination
test
On basis of carrier
particle used
12. COAGGLUTINATION TEST
S.Aureus
(Cowan 1)
ANTIBODY (IgG)
S.Aureus
(Cowan 1)
ANTIGEN (in patient sreum)
LATTICE
FORMATION
S.Aureus
(Cowan 1)
S.Aureus
(Cowan 1)
S.Aureus
(Cowan 1)
PROTEIN A
How it works?
13. LATEX AGGLUTINATION TEST...
The carrier particle is Latex or polystyrene latex
Brains behind this: C M Plotz and J M Singer
Accidently discovered IgG adsorbed naturally
to polystyrene latex particles (1953)
15. LATEX AGGLUTINATION TEST- USES
• Carrier + Antibody- detection of antigens-
CRP,RA factor, HCG, Hepatitis B
• Carrier + Antigen- antibodies to meningococci,
H.influenzae type b
16. Large number of antigens can adsorbed on carrier
Better visualization of Ag-Ab reaction due to larger
particle size of Latex beads preventing previous
cumbersome process involved in precipitation
reactions (no sophisticated equipments required)
Latex particles do not cross-react with other
antibodies
Less time consuming
LATEX AGGLUTINATION TEST- ADVANTAGES
17. HEMAGGLUTINATION TEST
The carrier particle is Red Blood Cell/Tanned
blood cell (Goose RBCs preferred)
Brain behind this: George Hirst (1942)
23. AGGLUTINATION TESTS IN OUR LAB IN A
BIRD’S EYE VIEW
ASO titre
RA factor detection
CRP
KIT- Syphicheck
Infectious mononucleosis (Immutex)
24. LET’S END BY LOOKING AT RECENT ADVANCES
• Determination of anti-streptolysin O antibody titer by a
new passive agglutination method using sensitized
toraysphere particles.
25. THANK
YOU
References from:
Anantnarayan and
Paniker’s Textbook of
microbiology
C.P. Baweja’s Textbook
of Microbiology
Subhash Chandra
Parija’s Textbook of
microbiology and
Immunology
American Society for
microbiolgy-Journal of Clinical
Microbiology