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Introduction of Hair Perforation Test

The hair perforation test is very useful to test for dermatophytes to differentiate Trichophyton and Microsporum species.

Test Requirements for Hair Perforation

• Blade
• Specimen: hair
• Distilled water
• Water vial
• Autoclave
• Microscope
• LPCB stain
• Quality control strains ( Trichophyton  mentagrophytes: Positive while Trichophyton rubrum: Negative)

Test procedure of Hair Perforation Tests

1. Take 10-20 hairs.
2. Cut blonde pre-pubertal hair into short pieces i.e. 1 cm.
3. Autoclave hair at 121 °C for 10 minutes and store in a sterile container.
4. Place 10- 20 short pieces of hair in 5 ml water in a vial.
5. Inoculate with small fragments of the test fungus.
6. Incubate at room temperature.
7. Individual hairs are removed at intervals up to 4 weeks and examined microscopically lactophenol cotton blue (LPCB) stain. Isolates of Trichophyton  mentagrophytes produce marked localized areas of pitting and marked erosion  (wedge-shaped perforations) whereas those of Trichophyton rubrum do not.

Result Interpretation of Hair Perforation Tests

Hair Perforation Test Positive: fungi pierce hair-producing wedge-shaped perforations

Hair Perforation Test Negative: Absence of wedge-shaped perforations

Test: Negative as shown above image below video.

Hair Perforation Test Positive organisms

1. Trichophyton mentagrophytes and
2. Microsporum canis.

Further Reading

1. A Text-Book of Medical Mycology. Editor: Jagdish Chander.  Publication Mehata, India.
2. https://www.science.gov/topicpages/h/hair+perforation+test
3. https://mycology.adelaide.edu.au/laboratory/hair/
4. https://www.researchgate.net/publication/19255784_Evaluation_of_human_hair_sources_for_the_in_vitro_hair_perforation_test