Final answer:
Wiping the puncture site with alcohol is crucial to prevent infection by killing bacteria, fungi, and certain enveloped viruses, with the added benefit of rapid evaporation without residue.
Step-by-step explanation:
It is important to wipe the puncture site with alcohol beforehand to prevent infection. Alcohols are effective in killing bacteria, fungi, and certain viruses, particularly those that are enveloped. The reason behind using alcohol for cleaning a wound is two-fold: it denatures proteins and disrupts microbial cell membranes, leading to the death of the pathogen. However, alcohols are not effective in the presence of visible dirt and are not sporicidal. Additionally, they evaporate quickly due to their volatility, which is useful in a clinical setting to rapidly prepare the skin for an injection without leaving residues.