Biological samples are materials collected from living organisms for scientific analysis. These samples can include blood, saliva, urine, tissues, or even cells. They are used in various fields such as medicine, genetics, and environmental science to study health, disease, and biological processes. Researchers analyze biological samples to gain insights into the functioning of organisms and to develop treatments for diseases. For example, DNA extracted from blood samples can help identify genetic disorders, while tissue samples can be examined for signs of cancer. Proper collection and storage are crucial to ensure the accuracy of the results.