Basics
- Blood for laboratory analysis is sometimes obtained by skin puncture rather than venipuncture.
- Sites for skin puncture include the finger, heel (in infants), or earlobe. To perform skin puncture: first select the site; then:
- Apply a warm compress to the site to increase blood flow.
- Clean the area with 70% alcohol.
- Thoroughly dry the site with a gauze sponge.
- Firmly prick the site with a lancet.
- To avoid diluting the blood sample with tissue fluid, wipe away this first drop of blood and do not milk the surrounding tissue.
- Collect the blood in a capillary tube, on a slide, or onto a test strip.
- If using a capillary tube, hold it horizontally and touch the end of the tube to the drop of blood without touching the skin. The tube will fill by capillary action.