Petri dish
The hair perforation test, also known as an "in vitro" hair perforation test, is a laboratory test used to help distinguish the isolates of dermatophytes, such as "Trichophyton mentagrophytes" and its variants. The test is performed by placing an organism into a Petri dish containing water, yeast extract, and hair. The Mayo Clinic's mycology laboratory has identified five common dermatophytes; "Microsporum gypseum", "Microsporum canis", "Trichophyton rubrum", "Trichophyton mentagrophytes", and "Trichophyton tonsurans".