Fingertip or earlobe.
Nonsterile disposable gloves; skin disinfectant (single-use alcohol swabs or single-use cotton swab with disinfectant solution); special blade or fine needle for puncturing skin; 2 special heparinized capillary tubes; 2 metal pins and 4 caps; magnet; sharps disposal container; equipment for infiltration anesthesia if necessary.
1. Warm (massage) the puncture site.
2. Puncture skin at a depth that ensures free outflow of a large drop of blood.
3. Fill the capillary tubes with blood; avoid introducing air bubbles inside.
4. Place the metal pins into the capillary tubes, close the tube ends tightly using plastic stopper caps, and mix the blood with the magnet.
Analysis should be performed immediately. If this is not feasible, the samples can be stored for ≤30 minutes on ice.