Serology is the study of blood serum, of which an important part is the response of the immune system to pathogens or induced substances. Immunological methods measure and characterise individuals' immune response for research and application. It is dependent on the principle of antigen-antibody reaction.
Antibodies are of 5 types; IgA, IgG, IgM, IgE, IgD. these occur in all individuals but different genetic variants c/a immunoglobulin allotypes.
Gm system- variation associated with the heavy chain of IgG. (also there are Am system, Inv system etc.)
[additional info- each has 2 heavy protein chains and 2 lights chains, heavy chains are diff for each class of antibody alpha, gamma, mu, epsilon and delta resp., light chains either kappa or lambda in any one molecule
allotypes- diff in constant region of antibodies].
Variation in these 5 antibodies is used in immunological study of man.
Methods
Antigen is injected in man and antibodies generated are separated and purified.
antibodies studied electrophoretically(quantity) as well as for amino acid composition.
Agglutination. Specific antigens attacked by the antibody and clump together to create agglutinate. It helps in diagnosing specific antigens, matching blood groups and study antigens.
Immunoassay. biological test that measures the presence or concentration of a macromolecule. Antibodies can identify specific molecules in a mixture of molecules and bind with it. Used in pregnancy test. ELISA test for HIV AIDS. Anti doping analysis.
Immunoprecipitation. Using antibody to bind to a specific protein in a solution then isolating precipitate and extracting it.
immunoelectrophoresis- diff antibodies present in sera are separated using an electrical gradient and levels are studied against benchmark levels.
Applications
Study structure function and cellular control of immunoglobulins
Detection of pregnancy, or doping
diagnose diseases- HIV by ELISA, immunodeficiency diseases like IgA deficiency, Wilcot Aldrich syndrome
genetic counselling of parents
Forensic science- for identification of individuals as antibodies can be used as genetic markers
testing for histocompatibility before organ transplantation
Treatment. antibody Infliximab in rheumatoid arthritis. (NO)