BIOTECHNOLOGY Is a new industry which uses organisms and their cellular, subccllular or molecular components to provide foods, services and environmental management It combines the principles of the btosclences with technological expertise, and often involves Inlegrat ton ol such advanetd disciplines as biochemistry, cell biology, chemistry, genet les, chemical engineering process engineering and com puter science.

The techniques of biotech nology are finding applkalton In many industries and re search fields, leading to prod ucts and processes that con tribute to a cleaner environment. improved diagnosis and treatment of diseases, more vigorous food crops, and alternatives to petroleum as a source of energy.

Among the most promising areas of research and devel opment arc the recombinant DNA (rDNA) and monoclonal antibody technologies. These two fields of biotechnological research have greatly expanded our knowledge of how living things grow, reproduce, and protect themselves against disease. A third major area of industrial research and development is bioprocess technology that will enable firms to produce cost-effective large quantities of highly purified products

Recombinant DNA

Technology

The methods used tn rDNA’ technology are fairly simple We take, for example, the gene for insulin production in hu mans and paste it into the DNA of Escherichia colt, a bacterium that inhabits the human digestive tract. The bacterial cells divide very rapidly. making billions of copies of themselves, and each bacterium carries in its DNA a faithful replica of the gene for Insulin production.

One approach to transfer the gene embodying the in struetton for insulin produc tton would be to cut the ap proprtate gene from human DNA and paste, or splice, it Into plasmid DNA. a special kind of DNA that takes a ctreu tar form and can be used as a vehicle for this editing Job Our "scissors’ are the class of cn zymes called restriction en zymes There are well over a hundred restriction enzymes, each cutting in a very precise way a specific base sequence of the DNA molecule. With these scissors used singly or in various combinations, the segment of the human DNA molecule that specifies insulin production can be isolated. This segment is "glued" into place using an enzyme called DNA Hgase. The result is a recombinant DNA molecule. When this recombinant plasmid DNA is Inserted into E. coll, the cell will be able to process the instructions to assemble the amino acids for insulin production. More importanl. the new Instructions are passed along to the next gen oration of E. coli cells In the process known as gene cloning.

This highly simplified de scriptlon of rDNA technology does not fully convey the enormous complexity or awesome economy arfd efficiency of genetic processes. But we can begin to understand how. by usipg rDNA, it is possible to produce substances of medical and economic value.

Applications of Recombinant DNA Technology

1. Gene mapping — e.g. map of human genome

2. DNA probes — detection of genetic disorders — diagnosis of Infectious diseases

— crime-solving by DNA finger probes

— detection of microorganisms that cause food poisoning

3. Gene replacement — gene therapy, e.g. in Cystic fibrosis

4. Genetically altered microorganisms with the ability to produce foreign proteins, e.g. vaccine, insulin. growth hormone, erythropoietin

5 Genetically Improved crops, e.g. resistance to disease and pests

6. Genetically altered animals (transgenic animals) :

— animals that produce useful human proteins e.g. tissue plasminogen activator

— animal models for hu man disease

— improved animal breeds

— animal models to test suspected cancer-causing agents and envtronmental hazards

7. Development of bacteria that make herbicide and other pesticide compounds

Monoclonal Antibody Technology

Our natural defenses against infectious agents are antibodies. proteins that seek out the antigens and held to destroy them. Antibodies have two very useful characteristics. First, they are extremely specific; that Is, each antibody binds to and attacks one particular ' antigen. Second, some antibodies, once activated by the occurrence of a disease, continue to confer resistance against that disease. The conventional method had been to inject a laboratory animal with an antigen and. then, after antibodies had been formed. collect those antibodies from the blood scrum. There are two problems with this method: it yields antiserum that contains undesired substances: and it provides a very small amount of usable antibody.

Monoclonal antibody tech nology allows us to produce targe amounts of pure antibodies. In monoclonal antibody technotogy. tumor cells that can replicate endlessly are fused with mammalian cells that produce an antibody. The result of this cell fusion is a "hybrldoma" that will continually produce antibodies. These antibodies are called mono clonal antibodies because they come from only one type of cell; antibodies produced by conventional methods, on the other hand, are derived from preparations containing many kinds of cells, and hence arc called polyclonal. Because the selected hybrid cells produce only one specific antibody, they are more pure than the polyclonal antibodies produced by conventional techniques.

AppScations of Monoclonal Antibodies

1. Diagnostic procedures for the early detection of diseases and Infectious agents

X Quantifying low levels of hormones and peptides

3. Antirejection agent in organ transplantation

4. Tissue typing

5 Tumor location and pos

sibility of selective elim ination of tumors

Bioprocess Technology

Bioproccss technology is based on the principle of combining living matter (whole organisms or enzymes) with nutrients under the conditions necessary to make the desired end product.

BlOprocesses have become widely used in several fields of commercial biotechnology, such as production of enzymes and antibiotics. Because bioprocesses use living material, they offer several advantages over conventional chemical methods of production : they usually require tower temperature. pressure, and pH; they can use renewable resources as raw materials; and greater quantities can be produced with less energy consumption.

As advances in bioprocess technology, particularly sepa ration and purification tech niques, are made, commercial firms will be able to economically produce these substances in large amounts, and thus make them available for use in medical research, food pro cessing, agriculture, pharma ceutlcal development, waste management and numerous other fields of science and industry.

Source : Industrial Biotechnology Association