What is a primary use of Lactophenol Cotton Blue stain in fungal studies?

• A. Temporary wet mounts for staining inocula from culture
• B. Fungicidal and sporicidal
• C. Permanently fix slides
• D. Staining bacterial capsules

Answer: (A)

Lactophenol Cotton Blue is used to visualize fungal structures by staining and mounting them for light microscopy. The cotton blue binds to chitin in the fungal cell wall, coloring hyphae, spores, and conidia so their morphology is easy to see, while the phenol acts as a clearing agent and disinfectant. This combination makes it ideal for temporary mounts of fungal cultures to study their microscopic features. It is not a method for permanently fixing slides, it isn’t intended as a fungicidal or sporicidal treatment, and it’s not used for staining bacterial capsules.