Aspiration
Bone marrow aspiration is often one of the first aspects of a bone marrow test. With a bone marrow aspiration, a doctor uses a syringe with a large, hollow needle to extract some of the liquid bone marrow from the body. The bone marrow is often taken from the pelvis because it is a large bone with abundant marrow, and can also be easily accessed with minimal risk of puncturing major blood vessels or damaging nerves. The liquid bone marrow is then examined under a microscope for abnormalities. Bone marrow is responsible for making up many of the cells that are present in the blood. Different cells in the bone marrow are in charge of producing different kinds of blood cells, so many different blood problems begin in the bone marrow. The cells from the bone marrow can be looked at under a microscope and examined for abnormal cells or for unusual amounts of certain cells.
Biopsy
Bone marrow biopsies are often the second stage of a bone marrow test. Although somewhat more invasive (because the needle goes farther into the bone and takes out solid bone marrow, not liquid), bone marrow biopsies provide more information because they generally get more cells from the bone marrow and can also provide information about the structure of the bone marrow. Bone marrow biopsies are examined using a microscope, similarly to an aspiration, although technicians can also look for other problems, such as certain metals (like iron) getting deposited in the marrow.
Culture
Another type of test that can be done on the bone marrow is called a bone marrow culture. This test is done by taking bone marrow samples and incubating them with a special mix of nutrients called growth media. This is done to see if any bacteria or fungi are growing in the bone marrow, which can cause infections and fevers that are otherwise difficult to diagnose.
