The blood is usually drawn from a vein in the forearm or the hand. First, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube, or tourniquet, is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them. A very thin needle is gently inserted into a vein and the tourniquet is removed.
Blood flows from the vein through the needle and is collected into a syringe or vial.
The blood sample is sent to the laboratory for testing. After the needle is withdrawn, the puncture site is covered for a short time to prevent bleeding. No preparation is generally needed for this test. The doctor who orders the test will provide specific instructions if needed. Normal AFP levels depend on the age of the person.