Which of the following is a key step in preventing contamination during the venipuncture procedure?

Using antiseptic to clean the skin before the needle insertion is essential in preventing contamination during the venipuncture procedure. This step minimizes the risk of introducing pathogens from the skin surface into the patient's bloodstream, which can lead to infections and compromised sample integrity. Antiseptics, such as alcohol or chlorhexidine, are specifically designed to reduce the microbial load on the skin, ensuring that the area is as sterile as possible before the needle is inserted.

The act of cleaning the skin is a fundamental practice in phlebotomy, as it not only protects the patient but also ensures that the collected sample is free from contaminants that could affect laboratory results. Proper skin antisepsis is a standard protocol that is widely taught and reinforced in phlebotomy training, highlighting its importance in maintaining patient safety and the accuracy of test outcomes.