Biotechnology can be dfescribed in many different ways, but a straightforward definition is :

Biotechnology is the use of biological organisms or enzymes in the synthesis, breakdown or transformation of materials in the service of people.

The polymerase chain reaction has enabled scientists to make large quantities of DNA from tiny samples. This in turn has made much of the most recent and exciting DNA technology possible. The ability to sequence DNA, identifying genes and what they do, the Human Genome Project, and DNA fingerprinting – all depend for their success on this ingenious technique.

The Human Genome Project, which has sequenced the whole of the human DNA, has been a massive international effort of biotechnology. The results are being used to help design very specifically targeted pharmaceutical molecules. These will provide better treatments which can be given at lower doses. What is more, these new medicines should have relatively few side effects because they will work with our individual genetic makeup rather than against it.

The new DNA technologies are helping scientists develop many new medicines which should enable us to treat many diseases more effectively.

Knowledge of the human genome is also making it easier to test for genetic diseases. Gene probes have been developed to test for known genetic disorders. What’s more, in the future it seems likely that doctors will be able to find out our genetic tendency to develop diseases like cancer and heart disease. This in turn will help us to make lifestyle plans to help us remain healthy – choosing our diets, our exercise levels and our jobs to make sure we avoid situations our genes are not well-equipped to cope with.

One area of biotechnology which nearly everyone has heard of is genetic engineering. We now have genetically-modified organisms ranging from bacteria to cows and sheep which produce life-saving medicines including vaccines, insulin and blood-clotting factors. Genetically-modified bacteria can even make the lung surfactant needed to save the life of a premature baby. Hundreds of thousands of people benefit from the chemicals these very special organisms produce.

Gene therapy is another area of medical biotechnology which is still in the early stages of development. The hope is that gene technology will help scientists develop ways to correct mistakes in the DNA code which lead to genetic diseases such as SCID (severe combined immunodeficiency).

Medicine also benefits from many sensitive tests which indicate the presence or absence of substances in body fluids. Biotechnological advances in the use of immobilised enzymes and monoclonal antibodies mean these tests have become increasingly rapid and accurate in recent years. A common example is the pregnancy test in the picture (left). This used to take weeks – now it can be done at home on the first day of a missed period and the results are ready in minutes!

Cloning – making genetically identical copies of an organism – is not new biotechnology. Gardeners and farmers have being cloning plants for centuries. The new developments which have caused much controversy involve the cloning of mammals, from sheep to pigs to humans. The technology holds out many exciting possibilities for producing herds of genetically modified animals making useful medicines in their milk. There is also the very real possibility of producing new tissues for transplantation which would not cause any rejection problems – because they would be cloned from the patient themselves. But there are some real concerns about the ethics of this work and society is still deciding what is the right way to go.

More controversial developments in biotechnology involve research into the use of stem cells. These cells, taken from the hollow ball of cells which make up the early human embryo, have the potential to grow and develop into new tissues or organs to replace others which are worn out or diseased. This area of biotechnology is still at a very early stage but the potential for medical advances is enormous. The use of human embryos means that it is also, for some people, very controversial.

Most of the developments in biotechnology have taken place in a very short space of time, beginning with the revelation of the structure of the DNA molecule 50 years ago. The biotechnology timeline shows just how rapidly DNA technology has developed.