Antibody and Antigen Reaction

Introduction 

Antigen cobine with its specific antibody is an observable manner and the reaction between antigen and antibody is specific 




Uses : In the body : it from the basis of immunity agents infection disease.

                   It may lead to tissue injury in some hyper sensitive reaction and auto immune disease

                    2  Detection and quantitative of either antigen and antibody .


Characteristics :Reaction is specific and Antigen combine only with its homologous antibody . Intier molecular of antigen and antibody react  and not the fregments.

Antigen and antibody can combine in verifiny proportion antibody are generally 

bia valent all though IgM may have five or more combing sites.

A single antigen can cause different type of antigen, antibody reaction and single antigen can estimulate production of different classes antigen can estimulate production of different classes of immunoglobulin.


Types of antigen and antibody reaction 

  1. Precipitation reaction 
  2. Agglutination Reaction 
  3. Complament fixation test 
  4. Immunofluorescence
  5. Neutralization
  6. Radio immuno assay (RIA)
  7. Enzyme liked immuno sorvent assay (ELISA)
  8. Immune Chromatography
1. Precipitation: When a soluble antigen react with antibody in the presence of electrolytes  (NaCl) act an optimum temperature and PH, . The antigen precipitate and it is called precipitation. Precipitation may occur in liquid media or in gels such as agar, Agrose polyagramide. The precipitate usually sediment at the bottom of the tube.

2. Agglutination :  It is an Antigen and antibody reaction in which a preticulate antigen combine with its antibody in the presence of electrolytes at an optimum temperature and PH.
Resulting climbing of place batter with IgM antibody than with IgG antibody.



Types of agglutination test

  1. Slide agglutination test
  2. Tube agglutination test 
  3. Heterphilic agglutination test 

Passive agglutination test is 3 types 

  1.  Letex Agglutination test 
  2. Haem agglutination test 
  3. Coagulation
1. Latex agglutination test

• Poly stave latex particles are widely employed to adsorb several types of antigens 

• Latex particles can also be coated with antibody for detection of antigen 

• These tests are used for detection of Hepatitis B antigen , ASO, CRP, RA FACTOR, HCG, bacterial typing ( N. menigitidis) and many other antigen.