Why should the first drop of blood be wiped during a dermal puncture?

The first drop of blood should be wiped away during a dermal puncture to remove any potential contaminants from the skin surface, such as tissue fluid, dirt, or debris. This helps ensure that the sample collected is representative of the blood and not influenced by external factors. Additionally, wiping away the first drop can help minimize the risk of hemolysis or skewed results caused by interstitial fluid.