The Pap smear is the main screening test for cervical cancer and pre-cancerous changes. The Pap smear is a procedure used to collect cells from the cervix for cervical cytology testing. The health care professional first places a speculum inside the vagina. The speculum is a metal or plastic instrument that keeps the vagina open so that the cervix can be seen clearly. Next, using a small spatula, a sample of cells and mucus is lightly scraped from the exocervix. A small brush or swab is then inserted into the opening of the cervix to take a sample from the endocervix. The cell samples are then prepared so that they can be examined under a microscope in the laboratory.