Answer :
Final answer:
The ring finger is preferred for capillary puncture, and the lancet depth should not exceed 2.00 mm to minimize discomfort and prevent tissue damage.
Explanation:
The ring finger is the preferred finger for a capillary puncture, and the depth of the lancet should be no more than2.00 mm . This practice minimizes the risk of reaching bone, especially in infants or individuals with less subcutaneous fat, where bone can be closer to the surface. The ring finger is typically used because it generally has less calloused skin compared to the index finger or thumb, making it an ideal site for obtaining a blood sample. The depth guideline ensures that sufficient blood can be obtained with minimal discomfort and tissue damage.