Overhead Projector Sheet: An Alternative to Glass Slide in Cytology

Introduction: Oral exfoliative cytology (OEC) is used by pathologists for visualizing cellular and nuclear changes, especially for initial screening. Traditionally, glass slides are used for OEC. As OEC is commonly used as an adjunct to biopsy and for mass screenings, it is necessary to minimize the cost of the procedure. Aim: The aim of this study is to compare hematoxylin and eosin (H&E) as well as periodic acid-Schiff (PAS) staining quality of cytological smear on glass slide with that of overhead projector sheets (OHP). Materials and methods: Smears were taken and spread on glass slide and OHP sheet and each of such set was stained using H&E and PAS stains. Scoring was done based on cellular morphology, overall staining, and nuclear details, under 10x and 40x magnifications. Photographs were taken on 1, 7, 21, and 35 days of preparation. All parameters of smear were compared between glass slide and OHP sheet. Descriptive statistics and "quality index" were obtained for glass slide and OHP sheet (quality index = actual score obtained/maximum score possible) and compared. Results: There was no statistically significant difference between glass slides and OHP sheets for all smear parameters with H&E staining on quality index. With respect to PAS, glass slides had better score for nuclear details, in 40x magnification. Conclusion: Glass slides are current gold standard for smear preparation. Our study shows glass slides and OHP sheets show no quality difference, with respect to cellular and nuclear morphology. Overhead projector sheets have potential to be used in mass screening programs in resource-constrained settings because of its cost-effectiveness and ease of handling and storage.