Standardized thionin-eosin Y: a quick stain for cytology.

Two stains long used in exfoliative cytology, the hematoxylin-eosin Y and Papanicolaou stains, have not been standardized even today. Some dozens of hematoxylin and eosin and Papanicolaou staining recipes have been recommended in the literature. Consequently, the staining pattern of hematoxylin and eosin, and Papanicolaou stained cytological material varies from laboratory to laboratory. To a certain degree this is due to batch-to-batch variations of commercial samples of the natural dye hematoxylin (C.I. 75290). The present paper describes a simple, standardized and reproducible procedure using thionin bromide to replace hematoxylin in the hematoxylin and eosin stain.