Classic microscopic appearance, Microsporum canis

Note the abundant hyphae, thick walls, tapered (canoe-shaped) ends, rough surface, and knob at the end of some macroconidia (spores). Visualization of the hyphae is improved by using lactophenol cotton blue stain and allowing the specimen to sit for 15–30 minutes after staining. During this time, stain will be absorbed into the cells, enhancing visualization of the macroconidia. Scan slides at 10X first. This is an unusual specimen, in that there are large numbers of macroconidia. Microsporum canis typically has many fewer macroconidia. Lactophenol cotton blue stain; original magnification, 40X.