Collection of Bone Marrow Aspirate From Normal Volunteers

Background: Bone marrow is the soft material found inside most large bones of the body. Bone marrow produces red blood cells, white blood cells, and platelets that are released into the blood stream. Inside the marrow, these cells start off as young, immature cells called progenitor cells. Researchers want to study these cells in healthy people. Objective: To understand how progenitor cells change with age. Eligibility: Healthy people ages 18 and older Design: Participants will be screened with a questionnaire, a physical exam, and blood tests. Participants will have a bone marrow aspirate. They will be asked to lie on their stomach or side. A local anesthetic will be injected with a small needle under the skin at the site. A needle will then be placed through the skin and into the hip bone. A small amount of the liquid part of the bone marrow will be taken up into the needle. After the needle is removed, a pressure bandage will be placed on the site. Participants will be asked to become a repeat volunteer and have a bone marrow aspirate sample collected once every other year. They will have a physical exam and blood tests before each collection. The cells from the collection will be used for genetic testing and research. Participants will be in the study for as long as they remain healthy and willing to participate.