Routine cytological staining is commonly done using the Papanicolaou method, Papanicolaou Stain was originally used only to detect vaginal epithelial estrogen levels and pathogens such as Candida and Trichomonas in the genital tract, Orange G6 in combination with EA36 or EA50 stains the cytoplasm with distinctive colors of green, blue and pink. Most laboratories now use finished stains, so each stain should be noted for its modified optimal conditions, and the final cytoplasmic stain should be transparent and visible, and the nuclear chromatin should be easily discernible. Currently, the improved Barton's staining solution contains a variety of ions, with polychromatic staining efficacy, stained cytoplasm is bright, good transparency as well as the nuclear membrane, nucleolus, chromatin structure is clear. Nucleus staining solution is mainly Harris hematoxylin stain, cytoplasmic staining solution is mainly EA36 stain, EA50 stain; Papanicolaou stain is used for cell detachment specimens, the nucleus of the cell is blue or black, keratinized squamous cell cytoplasm is pink or orange.

Papanicolaou  is used for cytoplasmic staining, and hematoxylin stain is used for nuclear staining. EA36 is more suitable for gynecological cytology smear staining than EA50, such as screening for cervical cancer and precancerous lesions.