Medicine is an important field of application for biotechnology. Today, biotechnology makes it much faster and more reliable to identify the causes of diseases. Biotechnology can also be used to treat and cure diseases. 

Identifying diseases is easier and faster today than it was before. Microbes isolated from a patient sample can be grown in a culture dish and identified by their own specific characteristics such as colour and shape. In addition, the DNA of many disease-causing bacteria and viruses is known and can be identified through laboratory testing.

Once the disease-causing microbe has been identified, the disease it causes can be treated with, for example, antibiotics. Antibiotics are now produced in large quantities with the help of microbes. Vaccines produced from microbes have been developed to prevent viral diseases. Previously, vaccines were produced in animal cells, which was expensive and slow. Antimicrobial vaccines are also safer. Today, even edible vaccines are being developed in which the pathogen gene has been transferred to, for example, a tomato.

With the help of biotechnology and sub-genetic engineering, it is possible not only to identify pathogens such as viruses and bacteria, but also to detect diseases at the geneyic level. A blood sample can be used to examine an individual for a particular gene form or genetic defect that causes a certain disease. 

It is now possible to treat diseases caused by genetic defects with gene therapy. Gene therapy is an experimental technique that uses genes to treat or prevent disease. This technique may allow doctors to treat a disorder by inserting a gene into a patient's cells instead of using drugs or surgery. This can be done either by taking the patient's cells, culturing them in the laboratory and transfering the desired gene into them, or by injecting the harvested gene forms directly into the patient's tissue. Severe cancers or inflammatory diseases such as rheumatoid arthritis can be treated with this method.

In the laboratory, it is possible to grow various tissues, such as skin or the eye's cornea. Stem cells can be used to compensate for tissue damage. Stem cell treatments are used to treat the neurological damage caused by Parkinson’s and Alzheimer’s disease, diabetes, muscle damage and spinal cord injuries. Stem cells are able not only to change to any cell type, but also to divide. This makes it possible to cultivate them under precise laboratory conditions and direct them to grow into the desired cell type.