Which of the following is NOT a factor in blood sample contamination?

Using a sterile collection device is indeed not a factor in blood sample contamination. A sterile collection device is designed to be free from any microbial contaminants, ensuring that the sample obtained is as clean as possible. The use of such devices minimizes the risk of introducing any external pathogens into the sample.

In contrast, poor antiseptic technique, contact with non-sterile surfaces, and the patient’s skin flora can all contribute to the contamination of blood samples. Poor antiseptic technique may leave pathogens on the skin or surrounding areas, while contact with non-sterile surfaces can transfer bacteria or other contaminants to the collection equipment or sample. Additionally, the normal flora present on a patient's skin can contaminate the blood sample if not properly addressed during the venipuncture process. Thus, employing a sterile collection device is key to preventing contamination rather than being a contributing factor.