A simple method enables the study of microbial invaders of the stratum corneum in their in vivo arrangement. The method employs cyanoacrylate adhesives which, after application to the skin, polymerize rapidly and bond to the stratum corneum, allowing a coherent sheet of horn to be removed. The "skin surface biopsy" method involved 50 patients whose specimens were studied using enzyme histochemistry, scanning electron microscopy, as well as staining with PAS to determine infecting microorganisms in their in vivo setting. This technique allows quantitation of the microorganisms in the specimen, and it is demonstrated that specimens from patients with ringworm infections treated by topically administered corticosteroids have approximately four to five times more fungus present than do those from patients not so treated.
Marks R, Dawber RPR. In Situ Microbiology of the Stratum CorneumAn Application of Skin Surface Biopsy. Arch Dermatol. 1972;105(2):216-221. doi:10.1001/archderm.1972.01620050030005