The follicular biopsy.

The 'follicular biopsy' is an extension of the noninvasive 'surface biopsy' technique originated by Dawber and Marks. A quick-setting cyanoacrylate polymer is used to extract the contents of sebaceous follicles. The retrieved material can be examined histologically at the light or electron microscopic level. Many types of analyses may be performed; microbial density, lipid components (acne), mite population (Demodex), hair retention (trichostasis), penetration of topical drugs and chemicals, localization of enzymes, etc. The follicular biopsy is useful for studying the contents of sebaceous follicles in health and disease.