Lactophenol Cotton Blue (LPCB): Principle and Procedure for Fungal Staining

The Lactophenol Cotton Blue (LPCB) wet mount is most widely used method for the staining and observation of fungi.


LPCB is a stain used for making semi-permanent microscopic preparation of fungi. The LPCB stain has following three components :
Phenol : Kills any live organism.
Lactic acid : Preserves fungal structures.
Cotton blue : Stains the chitin and cellulose of the fungal cell wall intensely blue.


  1. Place a drop of 70% ethanol on a clean microscopic glass slide
  2. Immerse the specimen in the drop of alcohol
  3. Add one or at most two drops of the LPCB before the alcohol dries out
  4. Holding the coverslip between the index finger and thumb, touch one edge of the drop of mountant with a coverslip edge and lower gently avoiding air bubbles
  5. This preparation is now ready for examination
  6. Make the initial examination using low power objective. Switch to higher power (40X) objective for more detailed examination of spores and other structures



Aspergillus on LPCB Mount

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3 Responses to Lactophenol Cotton Blue (LPCB): Principle and Procedure for Fungal Staining

  1. S September 23, 2015 at 7:43 pm #

    The above genus, I believe, is Penicillium and not Aspergillus. Please check.

    • Allison January 8, 2018 at 3:31 pm #

      My thoughts exactly!

  2. priyanka.C February 24, 2017 at 1:32 am #

    it is nice to read. I can remember easily.
    thank you.

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