Guidance for obtaining a blood sample

It is important to do the following when obtaining a blood sample so that your test results will be accurate:

•      Wash your hands thoroughly with hot soapy water to remove contaminants and to increase vasodilation and blood flow to the fingertips.

•      Rinse your hands thoroughly and dry them properly with a clean paper towel to avoid contamination or dilution of the sample from wet hands.

•      Avoid the use of disinfectants, hydrogen peroxide, or alcohol before pricking the finger.

•      Discard the first drop of blood by wiping the site with a clean paper towel, and immediately obtain a second drop of blood on the fingertip. Be careful not to squeeze or ‘milk’ the fingertip near the puncture site to obtain the blood sample. If necessary, rather squeeze lower down near the base of the finger or the palm of the hand. If the fingertip is squeezed too close to the puncture, haemolysis will occur to the blood sample, which will skew the results.

•      If the blood has struggled to come out and you have to squeeze again, it is better to repeat the puncture on a different finger. Use the other hand if having to redo a test.

•      Use lancet needles of an appropriate diameter. Remember that you will need a decent size drop of blood, so if you have thicker skin or reduced blood flow in the fingertips, you may need a larger lancet to obtain an adequate blood sample.

•      It is important that the sample must be obtained in one go. You cannot partially obtain a sample and then attempt to obtain more blood from the same puncture. The reason being that blood starts to clot upon exposure to air and the clotting mechanism may interfere with the result. Haemolysis will also interfere with the results as mentioned above.