Pap stain was developed by George Nicholas Papanicolaou , the father of cytopathology in 1947. Pap stain is a polychromatic stain containing multiple dyes to differentiate cells in smear preparations of various bodily secretions. It is used for cervical cancer screening programme in gynaecology to detect precancerous and cancerous lesions of the cervix, the entire procedure is known as pap smear. It is also used in oral cancer screening programmes. Since the time of its invention, it has undergone various modifications from conventional method from regressive to progressive. It has undergone further modifications to rapid, UFP(ultra fast pap stain), MUFP(modified ultra fast pap stain), Enviro–pap( environmentally friendly, inexpensive pap stain) and REAP( Rapid, Economic, Acetic acid, PAP Stain). Each method has its own advantages and disadvantages. Each laboratory has its own staining protocol which should be standardized.