Taking a small amount of bone marrow to see if it is healthy. It can show if the bone marrow contains cancer cells. A local anaesthetic is put into the skin over the hip bone. A needle is put into the hip and a small amount of bone marrow sucked out. This is examined under a microscope. The test takes only a few minutes, but can be uncomfortable. Some people prefer to have a medicine to make them feel drowsy (sedative) as well as the local anaesthetic.