BONE MARROW
What is bone marrow?
Bone marrow is the spongy tissue present within certain bones that contains stem cells and precursors that produce white and red blood cells and platelets. In adults, cell-producing marrow is found typically in the hips, but also in the backbones (vertebrae), shoulder bones, ribs, breastbone, and skull.
What is the procedure?
A bone marrow biopsy generally takes place in a physician’s office or hospital. The selected area, usually the hip, is sterilized and anesthetized, and then a special needle is inserted into the marrow-containing bone. An instrument like a hollow tube is pushed into the bone and withdrawn to pull out a cylindrical piece of tissue (core biopsy). Some of the marrow and blood is also drawn up into a syringe (aspirate).
How is bone marrow tested?
Some of the liquid aspirate will be smeared onto slides, which can then be stained and examined under a microscope. The aspirate can also be used for flow cytometry, cytogenetics, and molecular testing. The core biopsy will be preserved in fixative and then embedded in wax so that very thin sections can be cut onto slides for staining and microscopic examination.
PERIPHERAL BLOOD
What is peripheral blood?
Peripheral blood is the blood circulating through the arteries and veins (not sequestered in the spleen, liver, bone marrow, etc.). It contains red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.
What is the procedure?
Blood draws are usually simple procedures and may be done almost anywhere: in a laboratory, a physician’s office, a hospital, or even sometimes at home. A tourniquet will be placed above the site where the blood will be drawn (usually the inner elbow). The skin will be sterilized, and a needle will be inserted directly into a vein. Blood is then collected into vacuum-sealed tubes that contain preservative agents.
How is peripheral blood tested?
Some of the blood may be smeared onto slides, which can then be stained and examined under a microscope. Blood can also be used for flow cytometry, and sometimes cytogenetics. Nucleic acids (DNA and RNA) can be extracted from the white blood cells for molecular testing.
SOLID TISSUE
What is solid tissue?
Solid tissue is any part of the body that is not suspended in liquid (i.e. almost everything besides blood and bone marrow).
What is the procedure?
Procedures for solid tissue collection vary widely, from small fine needle aspirations and core biopsies, to larger partial or even full organ removals. Depending on the complexity, the procedure may be done on an outpatient basis, or may require hospitalization.
How is solid tissue tested?
The tissue will be preserved in fixative and then embedded in wax so that very thin sections can be cut onto slides for staining and microscopic examination. Nucleic acids (DNA and RNA) can also be extracted for molecular testing.