Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains stem cells. The stem cells can develop into the red blood cells that carry oxygen through your body, the white blood cells that fight infections, and the platelets that help with blood clotting. Bone marrow is a spongy substance found in the center of the bones. It manufactures bone marrow stem cells and other substances, which in turn produce blood cells. Each type of blood cell made by the bone marrow has an important job. Red blood cells carry oxygen to tissues in the body. A person can live without bone marrow provided they receive regular blood transfusions. This is because all of the cells in the blood are produced in the marrow. Bone marrow is the soft, spongy tissue that is located in the medullary cavities (centers) of certain large bones. Healthy bone marrow is an essential part of the body, as it contains stem cells that produce blood cells and the cells that make up the immune system. Bone marrow donation is a surgical, usually outpatient procedure. You will receive anesthesia and feel no pain during the donation. Doctors use a needle to withdraw liquid marrow from the back of your pelvic bone via two small punctures.