“…Calcofluor White, a water‐soluble dye, was shown to exhibit selective binding to cell walls and has since been widely used as a fluorescent dye to visualise cell walls in fungi, bacteria, algae and higher plants (Darken, , ; Waaland and Waaland, ; Harrington and Hageage, ; Hoch et al ., ; Rasconi et al ., ; Zhou et al ., ; Mitra and Loque, ; Herburger and Holzinger, ; Ribas and Cortes, ; Snow, ). The staining specificity of Calcofluor White has not been resolved, although it clearly binds to cell walls composed of chitin, cellulose or other beta‐1,4‐linked carbohydrates (Maeda and Ishida, ; Albani and Plancke, ; Albani, ; Wysokowski et al ., ; Mitra and Loque, ). Calcofluor White has turned out to be a robust, cell‐wall‐specific dye and is compatible with the ClearSee protocol (Figure a), yet its excitation and emission maxima require two‐photon excitation or a 405‐nm laser that not all confocal systems are equipped with.…”