Typically, a blood sample is taken by inserting a needle into a vein, usually in your arm. Before your blood is drawn, an elastic band is tied around your upper arm to increase blood in the veins, and the puncture location is wiped clean with an antiseptic. A blood draw using a needle may cause a temporary sting. The blood draw normally lasts for less than a minute. Sometimes a blood sample is collected by puncturing the tip of a finger and drops of blood are collected onto a test pad, filter paper, or into a small tube.