Final answer:
The medical assistant must avoid reaching over the sterile field to maintain sterility and prevent contamination while assisting with a medical procedure.
Step-by-step explanation:
For the medical assistant to maintain a sterile field while assisting with a procedure, the most correct practice they should adhere to is to avoid reaching over the sterile field. This is essential to prevent contamination that could lead to infections such as sepsis. The sterile field should always be above the waist level to maintain its sterility, and the medical assistant should never touch it with bare hands. Instead, they should use sterilized gloves and appropriate surgical attire to protect both the patient and the field from contamination.
It is crucial for a medical assistant to follow standards of aseptic technique as published by professional organizations, such as the Association of Surgical Technologists. Such standards help maintain the high levels of cleanliness and sterility required for patient safety during medical procedures.