Antigen antibody interaction

interaction

1. Antigen antibody interaction Kalu ram sharma M.Sc (biotechnology) Manipal university jaipur

2. Antigen In immunology, an antigen is a molecule capable of inducing an immune response on the part of the host organism.

3. Antibody An antibody ( Ab ), also known as an immunoglobulin ( lg ), is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as bacteria and viruses.

4. Antibody

5. Antigen-antibody interaction The antigen-antibody interaction is a bimolecular association similar to an enzyme-substrate interaction, with an important distinction.

6. Antigen-antibody interaction Ag-Ab interaction is a specific chemical interaction between antibodies produced by B cells of the white blood cells and antigens during immune reaction. In the fundamental reaction in the body by which the body is protected from complex foreign molecules, such as pathogens and their chemical toxin.

7. Strength of Ag- Ab interaction The non-covalent interactions that form the basis of Ag-Ab binding include hydrogen bonds, hydrophobic interactions, and van der Walls interaction. Because these interactions are individually weak (compared with a covalent bond), a large number of such interactions are required to form a strong Ag-Ab interaction.

8. Visualizing concepts

9. The interaction between an Ab and an Ag depends on four types of noncovalent forces: (1) hydrogen bond:- in which a hydrogen atom is shared between two electronegative atoms. (2) ionic bonds:- Between oppositely charged residues.

10. (3) Hydrophobic interaction:- in which water forces hydrophobic groups together. (4) van der Walls interaction:- Between the outer electron clouds of two or more atoms.

11. Immunologic tests (1)Radioimmunoassay (RIA) (2)ELISA (3)Western Blot (4) Immunoprecipitation (5) Immunoflurescence

12. (1)Radioimmunoassay (RIA) It is very sensitive in vitro assay technique used to measure concentration of antigen (for example , hormone levels in blood) by use of antibodies.

13. (2)ELISA(Enzyme-Linked Immunosorbent Assay) ELISA is test that uses antibodies and color change to identify a substance. The ELISA has been used as a diagnostic tool in medicine and plant pathology , as well as a quality-control check in various industries. The following steps of ELISA:- (a)indirect ELISA (b)sandwich ELISA (c)competitive ELISA

14. ELISHA

15. (3)Western Blot The western blot sometimes called the protein immunoblot . Used to identification of specific proteins in mixtures. Proteins are separated on SDS-PAGE. Proteins then transferred to membrane.

16. (4) Immunoprecipitation Provides a quick and sensitive test for finding proteins. Binds Ab to synthetic bead support centrifuged.

17. (5) Immunoflurescence Provides a quick method for the identification of pathogens and lymphocytes. There are currently 2 methods employed:- (a)Direct staining (b)Indirect staining

18. Application Antigen-antibody interaction is used in laboratory techniques for serological test blood compatibility and various pathogenic infection. The most basic is ABO blood group determination , which is useful for blood transfusion.

19. References Kuby book www.google.wikipedia.com

20. Thank you