MICROBIOLOGY Essay Example | Topics and Well Written Essays - 500 words

MICROBIOLOGY - Essay Example IgD: - IgD has a serum concentration of 30Â µg/ml and constitutes about 0.2% of total serum immunoglobulin. It is the major membrane bound immunoglobulin expressed by mature B – cells and is involved in the activation of B – cells by antigen. c. In immediate hypersensitivity antigen binds to IgE on mast cells and basophils. This cross linking leads to degranulation with the release of biologically active substances contained in the granules. 5. a. In the ouchterlony method both antigen and antibody diffuse radially from wells toward each other, thereby establishing a concentration gradient. As equivalence is reached, a visible line of precipitation forms. This simple technique is an effective qualitative tool for determining the relationship between antigens and the number of different Ag-Ab systems present. ELISA Test: - An enzyme conjugated to an antibody reacts with a colorless substrate to generate colored reaction product. Enzymes used include alkaline phosphates, horseradish peroxides. ELISA test is used to detect the presence of antibodies and antigen. RIA: - RIA is a competitive binding assay in which fixed amounts of antibody and radio labeled antigen react in presence of unlabelled antigen. The labeled and unlabelled antigens compete for limited binding sites on the antibody. After reaction, the antigen is separated into free and bound fractions and their radioactive counts measured. The concentration of the unlabelled (test) antigen can be calculated from the ratio of the bound and total antigen labels, using standard dose response curve. 6. It is difficult to develop a natural system of Bacterial Taxonomy using the traditional technique of Taxonomy because bacteria are generally very small and have simple shapes, and hence their classification by shape is not an easy task. The revolution in Genomics will affect Taxonomy because with the coming of