Methyl Blue is a histology dye commonly used to stain collagen blue in tissue sections. The compound has been determined useful as a vital dye for interocular observations. Methyl Blue has been incorporated in Sabouraud agar for the identification of Candida albicans strains. The compound has also been incorporated in other histology staining procedures such as Mallory’s connective tissue stain.A histology stain for collagen in tissue sectionsMethyl Blue has been used:· to stain leaf disks for callose visualization within the cells· to incubate cells for 4′,6-diamidino-2-phenylindole (DAPI)/septa staining· as a marker for β-(1-3)-d-glucans or acidic phloroglucinol for the detection of callose and lignin