PASSIVE AGGLUTINATIONGROUP-K

• What is passive agglutination?• What are various types of passive agglutination tests?

AREAS OF INTERESTS…

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What is agglutination?

Particulate antigen + its specific antibody

Electrolytes at an optimal temperature and pHVisible clumping of

particles

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What is precipitation

reaction?

Soluble antigen + its specific antibody

Electrolytes at an optimal temperature and pH

Insoluble precipitate

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And what is Passive Agglutination??

Precipitation reaction

Agglutination testsco

nvert

ed

By attaching soluble antigens to the surface of carrier particles such as latex particles, bentonite, RBCs, etc.

ADVANTAGES OF PASSIVE AGGLUTINATIONAdvantage of Passive agglutination over precipitation tests are:• More convenient• More sensitive for detection

of antibodies• More sensitive for detection

of antigens (Reverse passive)

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

LATEX(0.8-1µ)

ANTIBODY

LATEX

LATEX

LATEX

LATEXANTIGEN (in patient

serum)

LATTICE FORMATION

REVERSE PASSIVE AGGLUTINATION…

Simplifying the course of study...

Passive agglutination

Coagglutination test

Latex agglutination test

Hemagglutination test

On basis of carrier particle used

COAGGLUTINATION TEST

Staphylococcus aureus (Cowan 1 strain) used

COAGGLUTINATION TEST

S.Aureus (Cowan 1)

Fc

FabFab

ANTIBODY (IgG)

ANTIGEN (in patient sreum)

PROTEIN AY

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?

LATEX AGGLUTINATION TEST...

The carrier particle is Latex or polystyrene latexBrains behind this: C M Plotz and J M Singer

Accidently discovered IgG adsorbed naturally to polystyrene latex

particles (1953)

LATEX AGGLUTINATION TEST...

How it works?LATEX(0.8-1µ)

AntigenLATEX

LATEX

LATEX

LATEX

LATTICE FORMATION

ANTIBODY

ANTIGEN

LATEX AGGLUTINATION TEST- USES

• Carrier + Antibody- detection of antigens- CRP,RA factor, HCG, Hepatitis B

• Carrier + Antigen- antibodies to meningococci, H.influenzae type b

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

HEMAGGLUTINATION TEST

The carrier particle is Red Blood Cell/Tanned blood cell (Goose RBCs preferred)

Brain behind this: George Hirst (1942)

HEMAGGLUTINATION TEST...

How it works?RBC

AntigenRBC

LATTICE FORMATION

ANTIBODY

ANTIGEN

RBC

RBC RBC

HEMAGGLUTINATION TEST- Examplified by Rose Waaler Test (Carrier-RBC )

RBC

Amboceptor(subagglutinating dose)

RBC

LATTICE FORMATION

RA FACTOR (in patient serum)

AMBOCEPTOR (Rabbit anti-sheep erythrocyte antibody)

RBC

RBC RBC

HEMAGGLUTINATION TEST- Examplified by TPHA (Carrier-Tanned RBC )

TannedRBC

Antigen(T.pallidum extract)

TannedRBC

LATTICE FORMATION

ANTIBODIES against T.pallidum (in patient serum)

ANTIGEN (T.pallidum extract)

TannedRBC

TannedRBC

TannedRBC

VIRAL HEMAGGLUTINATION AND HEMAGGLUTINATION INHIBITION TEST

What is Viral Hemagglutination?

RBC

VirusRBC

LATTICE FORMATION

VIRUS

RBC

RBC RBC

VIRAL HEMAGGLUTINATION AND HEMAGGLUTINATION INHIBITION TEST

What is Hemagglutination inhibition ?

VirusNO LATTICE FORMATION

VIRUS

RBCAb against VIRUS

RBCRBC

AGGLUTINATION TESTS IN OUR LAB IN A BIRD’S EYE VIEW

ASO titre

RA factor detection

CRP

KIT- Syphicheck

Infectious mononucleosis (Immutex)

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.

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 ImmunologyAmerican Society for microbiolgy-Journal of Clinical Microbiology