Biomedical Science Technique – Lactophenol Cotton Blue (LPCB)


Malgorzata Rekas and Marilena Ioannou


College, University, Specialist Biomedical

OER FEATURES: (bundle of 5 resources)

Biomedical science resources: Video

Transcript of Lactophenol Cotton Blue Video (DOC)

Transcript of Lactophenol Cotton Blue Video (PDF)

Multiple Choice Questions on LPCB (DOC)

Multiple Choice Questions on LPCB (PDF)


In the biomedical science laboratory, the identification of fungus is a standard microbiological technique. Often, the lactophenol cotton blue (LPCB) technique is carried out to provide a quick and easy method of staining fungi. Slides are prepared using special dyes and stains and are then observed under the light microscope. Samples of fungi can be grown in Petri dishes. Using an aseptic technique, fungal samples can be transferred onto a slide and stained with the dye.

The fungal structures are teased out using two sterile needles so that they can be viewed and identified under the microscope. Simply, a glass coverslip is placed on the slide and it is viewed wet under the microscope. The architecture of the filaments and fungal spores helps identify the type of fungus.

This is a typical microbiology technique performed in biomedical science laboratories to determine the presence of fungus in biological tissues.

How to Measure Zones of Inhibition or ZOI – Microbiology Resources

Open education resourcesBiomedical ScienceMicrobiology

Microbiology resources


Image: “Zone of Inhibition” animated resource.
Creative Commons BY SA.

Content Authors:                                                Level:

Marilena Ioannou and Malgorzata Rekas                       General interest

OER Features:

 Click here for: Animation of measuring ZOI

Click here for: Video of measuring ZOI on YouTube

Microbiology OER Description:

These OERs are microbiology resources explaining the fundamental principle of how to measure zones of inhibition or ZOI. This is a simple microbiology screening test to assess the effect of antibacterial agents on bacterial growth. Bugs are grown on agar plates and a round disc containing a known concentration of antibiotic is placed. If the bacteria is susceptible to the antibiotic, then there will be an area where it does not grow.

In an experimental situation, measuring the dimensions of the zone of inhibited growth can help compare the effects of different antibiotics and different concentrations.