Final answer:
The maximum depth for a heelstick puncture is 2.0 mm to prevent bone damage while collecting blood samples from infants.
Step-by-step explanation:
The maximum depth of a puncture for a heelstick is 2.0 mm for infants. This depth is recommended to avoid causing damage to the bone as the heel has only a small amount of tissue over the bone. The heelstick procedure is typically done to collect blood samples for newborn screening tests, and proper technique is essential to ensure the safety and comfort of the infant.