A blood sample can be taken from a finger or an arm. Blood can also be drawn via a line or a portacath, if applicable.
From a finger
The lab technician applies some ointment to the fingertip. The lab technician then presses a device against the fingertip and collects the drops of blood in a tube.
From an arm
An anesthetic ointment is first applied to your child's arm. In order to let the blood vessels stand out, the lab technician wraps a tourniquet around your child's arm, and draws it tight. The lab technician then wipes the arm clean and inserts a syringe into the blood vessel. The tourniquet is then loosened and the blood is collected in one or more tubes. After collecting the blood, the lab technician removes the syringe and presses down on the spot where the syringe had been inserted until it stops bleeding.
Via a portacath or a line
The nurse connects one or more tubes to the portacath or the line in order to collect the blood. After collection, the line or portacath is flushed with saline and heparin.
Should you need any further information, please feel free to ask.