Potentially precancerous changes in the cervix can be detected by cervical screening, using methods including a Pap smear (also called a cervical smear), in which epithelial cells are scraped from the surface of the cervix and examined under a microscope. The colposcope, an instrument used to see a magnified view of the cervix, was invented in 1925. The Pap smear was developed by Georgios Papanikolaou in 1928. A LEEP procedure using a heated loop of platinum to excise a patch of cervical tissue was developed by Aurel Babes in 1927. In some parts of the developed world including the UK, the Pap test has been superseded with liquid-based cytology.