On the staining of human tissue-cultured (Chang) conjunctival cells with rose bengal and lissamine green

PurposeTo assess the staining of Chang conjunctival epithelial cells with rose bengal and lissamine green.MethodsA human (Chang) conjunctival epithelial cell line was grown on plastic plates in 10% foetal calf serum-supplemented medium in 5% carbon dioxide–air at 37 °C. Cells were examined daily between days 2 and 10 of culture, reaching confluence after 7 days, for overall appearance before and after exposure for 3 min at 37 °C to solutions of either rose bengal or lissamine green (dissolved in saline, PBS or balanced salts solution). Measurements of nucleus and cell size were made on some confluent cultures.ResultsChang cells, regardless of the growth state or the vehicle used, stain very intensely with rose bengal, with the nucleus of the cells showing the most notable dye uptake. Cultures showing such intensive staining with rose bengal were consistently non-staining with lissamine green. Nucleus size, based on measurements of the long dimension (NUCLONG) were the same for rose bengal or lissamine green exposed cells (averaging 19.5 ± 2.4 μm and 18.8 ± 2.9 μm, respectively). Cell size at confluence, based on measurements of the long dimension of lissamine green-exposed cells (LONG), averaged 40.5 ± 7.2 μm. The cytoplasm-to-nucleus ratio (based on LONG–NUCLONG/NUCLONG) averaged 1.177 ± 0.406 (i.e. approximately a 1:1 ratio).ConclusionsCultured Chang conjunctival cells stain intensely with rose bengal, but the same is not seen with lissamine green. The cell morphology is indicative of flattened epithelial cells.