principle of antigens and antibodies

1. PRINCIPLE OF ANTIGENS
AND ANTIBODIES

2. PRINCIPLE OF ANTIGENS AND
ANTIBODIES

3. ANTIGENS
Antigen – any substance capable of
inducing antibody formation
Erythrocytes can be immunogenic or
antigenic if their membrane contains a
number of areas recognized as foreign,
called epitopes

4. CHARACTERISTICS THAT INFLUENCE THE
IMMUNOGENICITY OF A SUBSTANCE:
1. Foreignness: the greater the degree of antigenic determinant is
recognized as non-self, the more antigenic
2. Molecular weight: the larger molecule, the greater it is likelihood of
processing unfamiliar antigenic determinants on its surface, hence
better the molecule functions as an antigen
3. Structural stability: unstable structure molecules are poor antigens
eg: gelatin
4. Structural complexity: more complex antigen, more effective it will
be complex proteins, better antigens
5. Route of administration: intravenous and intraperitoneal routes
offer stronger stimulus than subcutaneous or intramuscular routes

5. ANTIBODIES
• Antibody – a protein (immunoglobulin) produced in
response to a foreign substance or antigen
• Five major immunoglobulin: IgG, IgA, IgM, IgD and IgM
• Blood group antibodies are almost exclusively IgG, IgM and
IgA