Where is nuclear DNA primarily found in the body?

Nuclear DNA is primarily found in the cell nuclei of living organisms, which means that any tissue containing cells with a nucleus can provide this type of DNA. White blood cells are particularly noteworthy because they are one of the few cell types in the body that are generally accessible for DNA extraction without significant destruction of the tissue. These cells are part of the immune system and are produced in the bone marrow, making them abundant and a reliable source of nuclear DNA for forensic or genetic analysis.

While muscle tissue, skin cells, and hair follicles can also contain nuclear DNA, the most consistent and practical source from the options provided is white blood cells. Muscle cells and skin cells may not be as readily available in certain contexts, and hair follicles, although containing nuclear DNA in some cases, are not as reliable, especially when the hair is shed (as opposed to being pulled out, which may include the follicle). Therefore, focusing on white blood cells highlights their role as a primary source for nuclear DNA in forensic investigations.