DNA (Deoxyribonucleic acid) is found in almost every cell of the human body. Primarily, DNA is located in the nucleus of the cell (called nuclear DNA), where it is organized into chromosomes containing the genetic instructions for the organism. In addition to the nucleus, a smaller amount of DNA is found in the mitochondria (called mitochondrial DNA or mtDNA), which are structures in cells responsible for producing energy. DNA can be extracted from various biological samples such as blood, saliva, hair (with root), skin cells, nails, bones, teeth, and bodily fluids, making it accessible for various types of genetic testing and forensic analysis.