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 doctors, 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 doctor. The sample is obtained by needle puncture and withdrawn by suction through the needle into a special collection tube. The procedure usually takes just 3 minutes and hurts just a bit, typically when the needle is inserted or withdrawn.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 doctors and nurses who have had specialised training. A local or general anaesthetic is used, depending on the procedure, so the patient remains comfortable. These kinds of tests are requested only when there is evidence of a problem. Your doctor and the medical staff will usually devote more time to explaining these procedures and why they are needed.