A Lactofuchsin mount (also spelled Lacto-fuchsin or Lacto-Fuchsin) is a technique used for mounting fungi with hyphae on a microscope slide for examination.[1] The main advantage of a lactofuchsin mount is that if performed correctly, it preserves the structure and arrangement of any hyphae that are present.
To examine the hyphae of fungi under a microscope, a wet mount is essential. While this is possible to do with a water based mount, a better result can be obtained with lactofuchsin mounting fluid, which both sticks to the cell walls and colours the cell walls red in the process. Lactofuchsin, a 1% solution of basic fuchsine in lactic acid,[2] dries much slower than water, so the slide may be preserved for a longer period, particularly if the edges of the finished slide are sealed, for example with clear nail polish.[3] In addition, the refractive index of the fluid is significantly different to that of the cell walls, which provides a stronger visual contrast of the cell walls against the background.
A significant disadvantage of Lactofuchsin is its cost; prices are over US$100 for a small 20mL bottle. Only a few drops are used for each mount. Lactofuchsin is poisonous.