Santhakumar Raja

Antibody mediated immunity refers to the destruction of antigens by producing antibodies, and as the antibodies are present in body fluids (humours), this type of immunity is also called humoral immunity. B-cells cannot bring about humoral immune response but needs the cooperation of other cells such as macrophages (f), T-helper cells (TH), and dendritic cells possessing high

Cell-mediated immunity is an immune response that does not involve antibodies or complement, but rather involves the activation of macrophages, natural killer cells, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. Historically, the immune system was separated into two branches, cellular immunity; for which the protective function of immunisation

Human insulin was the first recombinant-derived product. It is used for the treatment of diabetes. Fredrick Sanger and his co-worker identified the insulin structure stating that it is made up of two polypeptide chains of A and B with a total 51 amino acid units (21 in A-chain and 30 in B-chain) held by disulphide

Interferons are low molecular weight proteins produced by virus infected cells, which in non-infected cells can induce the formation of a second protein. This protein has the ability to prevent transcription of any viral mRNA produced in that cell. Interferons exhibit antiviral activity, anti-proliferative activity, and many effects on the immune system. Interferons on the

Genetic engineering has an important role to play in the production of medicines. Microorganisms and plant-based substances are used for producing various drugs, vaccines, enzymes, and hormones at low costs. Genetic engineering involves the study of inheritance pattern of diseases in man and collection of human genes that provide a complete map for inheritance of

In recombinant DNA technology, many different techniques are used to achieve different requirements or to obtain proper information so that an exact inference can be drawn out during genetic engineering. Gel electrophoresis, blotting techniques, bot-blot hybridisation, DNA sequencing, artificial gene synthesis, polymerase chain reaction, colony hybridisation, are some of the important techniques used. Gel Electrophoresis

To express a cloned gene (for a desired product) in a transformed cell means that it has to transcript and translate. Sometimes functional proteins are produced by post-translation modifications. Protein synthesis is based on the encoded information in the sequence of the DNA strand bases. Structural gene directs the cells machinery for sequential linear arrangements

The HRT method is utilised for recombinants without introns. The most difficult step in applying hybridisation is obtaining a suitable probe. If the target DNA is represented with highly abundant mRNA, a small number of cDNA clones can be screened and the target gene can be identified by sequencing or hybrid released translation. In HRT,

The replica plate method is used in genetic engineering for identifying transformed bacterial cells (cells containing foreign DNA). Only some of the cells transformed with a specific DNA may actually have foreign DNA. Thus, it is essential to screen those cells having foreign DNA by the technique of colony hybridisation (only for bacterial cells) figure.