Introduction Eliminated Easy To Reach From Within Sources

Samples From Within
Some samples can only be obtained by breaking through the body’s protective coverings (e.g., skin). Blood samples and tissue specimens, for example, are obtained in minimally invasive procedures conducted by specially trained physicians, nurses, and medical personnel.

Blood—Blood samples can be collected from the capillaries and veins by a trained phlebotomist; arterial blood samples are drawn by a specially trained nurse or physician. The sample is obtained by needle puncture and withdrawn by suction through the needle into a special collection tube. The procedure usually takes just 3 minutes and hurts just a bit, typically whent the needle is inserted or withdrawn. See Tips on Blood Tests for more information.

Minor Surgical Procedures—Samples of bodily tissue, spinal fluid, and bone marrow can be collected in minor surgical procedures conducted by physicians and nurses who have had specialized training. A local or general anesthetic is used, depending on the procedure, so the patient remains comfortable. These kinds of tests are ordered only when there is evidence of a problem. Your physician and the medical staff will usually devote more time to explaining these procedures and why they are needed.