METHYLENE BLUE FOR MICROSCOPY
Methylene Blue is a popular alkaline stain used to view microscopic life in brilliant color. It helps make cells show up against their background, where their shape can help you determine what they are (their morphology).
Methylene blue is used to stain blood films/smears used in cytology and to stain RNA or DNA for viewing under the microscope or on hybridization membranes.
Methylene Blue is a cationic stain (positively charged blue dye); and binds to negatively charged parts of the cells, such as nucleus (DNA) and RNA in the cytoplasm (with lower affinity).
methylene blue, Gram safranin, or Gram crystal violet are useful for staining most bacteria. These stains will readily give up a hydroxide ion or accept a hydrogen ion, which leaves the stain positively charged.