To clarify a bit further here;
A Surgical Tech (ST, or if certified, CST) is an instrument assistant during surgery. Scrub techs assist RN's in planning and preparing the OR for a surgical case. They prepare a back table of instrumentation and set up the mayo stand providing the surgeon and his assistant with the appropriate intrumentation/supplies for the case. They are responsible for maintaining the sterillity of the surgical field before and during the procedure, keeping track of countables, and applying a dressing to the surgical site. All of this is done by a scrub tech after he/she 'scrubs
' hence the misnomer "scrub nurse".
A surgical nurse is a Registered Nurse, cabable of both scrubbing and circulating in surgery. The RN plans and prepares an OR for surgery, assesses and provides nursing care pre-op and intra-op for patients. an RN is an advocate for patients at a time when they are most vulnerable and unable to advocate for themselves.
In the northeast, a scrub tech is a graduate of a 1 year program designed to teach the basics in aseptic technique, surgical procedures, A&P, types of instrumentation, and handling of instruments.
In most states the circulator must be an RN, though RN's are quite capable of scrubbing and circulating.