• Mounting Media in Diagnostic Mycology: The most widely utilized universal mounting and staining reagent for temporary microscopic mounts of fungal mycelia, conidiophores, and spores is Cotton blue in lactophenol (LPCB).
• Chemical Constituents and Functions:
• Phenol: Rapidly kills fungal hyphae and inactivates autolytic enzymes.
• Lactic acid: Preserves fungal cellular morphology and structures.
• Glycerol: Maintains an osmotic balance and prevents the mount from drying out.
• Cotton blue (Aniline blue): Acidic stain that binds intensely to fungal cell-wall chitin, staining hyphae and reproductive spores bright blue.
• Conclusion: Cotton blue in lactophenol is the standard mounting medium (Option 2).

Correct option: (2) Cotton blue in lacto-phenol