This study was aimed at comparing the commonly used metachromatic stains viz., Papanicolaou stain, Wright-Giemsa, Toluidine blue and Methylene blue in the assessment of cell types of the oestrous cycle in rats. Eight female Sprague-Dawley rats aged 8-9 weeks were used for this assessment. Cotton Swabs were gently inserted in the animals vagina to obtain cells from which they were then transferred to glass slides for staining and evaluation under microscopy. The different cell types were compared for their morphological features and clarity of cellular detail under all four stains. The application, advantages and limitations of all stains were then discussed. It was concluded that the selection of the most effective stain in the assessment of vaginal cytology depends on their application to clinical or research which was based on the cellular detail of interest, time, cost and availability of each staining procedure.
KEY WORDS: Papanicolaou; Wright-Giemsa; Methylene blue; Toluidine blue; Vaginal cytology.