PetriKey

Lab method

Lactophenol cotton blue

Mounting stain for mold morphology

LAK-toe-FEE-nol

stainfungusmoldmorphologymounting

High-yield clue

Lactophenol cotton blue is the go-to mount for studying mold structures like conidiophores and macroconidia.

Overview

A mounting-fluid stain concept for examining fungal (especially mold) morphology, where cotton blue dye colors chitin in cell walls while phenol and lactic acid preserve structures.

Classification

  • Mounting-medium stain concept
  • Mold morphology method
  • Chitin-binding dye
  • Light microscopy

Lab & identification clues

  • Cotton blue colors fungal cell walls
  • Preserves hyphae and fruiting-body shape
  • Used with tease/tape mount vocabulary
  • Reveals conidia and spore arrangement

Associations

  • Aspergillus conidiophore recognition
  • Dermatophyte macro/microconidia study association
  • Mold identification vocabulary

Commonly confused with

  • KOH preparation
  • Calcofluor white stain

Your notes

Original concept summary for coursework. Sources checked: OpenStax Microbiology 2e and NCBI Bookshelf Medical Microbiology; reviewed 2026-06. Describes vocabulary and interpretation concepts only; not a lab protocol and not for handling specimens or identifying patient isolates.

OpenStax: Microbiology 2e staining, media, and biochemical-test foundationssourceNCBI Bookshelf: Medical Microbiology diagnostic concept foundationssource