There’s nothing like a bad hair day! For me, the worst is the dry California heat, and when that happens- static is my name.
The in-vitro hair test is a fun one to set up! This test is useful in the differentiation of certain dermatophytes, particularly Trichophyton mentagrophytes and its variants which are positive for this test. The recipe calls for blonde hair from a prepubescent human, and luckily I have co-workers who have blonde family members. I certainly was not a contributor to science in this regard! Genetically impossible. ;)
So how can we tell it is positive? If you take a look at the V shaped notches in the hair under the microscope, you can see the fungus has invaded the hair follicle and created those “wedges”. A negative hair test would just have fungus all around, with no notches.