A novel in vitro stripping method to study geometry of corneocytes with fluorescent microscopy: example of aging skin.

BACKGROUND/PURPOSE To develop modification of stripping method allowing high-resolution fluorescent visualization of corneocytes of human skin in vitro. To validate the method, the measured corneocyte areas on skin flakes are collected from individuals of different ages. MATERIALS AND METHODS Two complimentary fluorescent dyes were used sequentially. First the adhesive layer of the stripping tape was stained with a cationic dye (rhodamine 640). This tape was used to collect skin flakes. Then both the tape and collected flakes were stained with anionic dye (fluorescein). The fluorescence of the adhesive tape exposed to the second staining is substantially decreased due to the mutual quenching of the dyes. Thirteen healthy, 6-86-year-old males participated to validate the method. The measurements were done on backhand and forearm. RESULTS The method allows high-resolution imaging of corneocytes by means of fluorescent microscopy. Both absolute areas and the dependence of corneocyte areas on the individual age are in good agreement with the data reported previously. CONCLUSION The developed method is fast and easy. It requires minimum interaction with the individual and allows using a broad variety of fluorescent dyes that may be potentially unsafe but beneficial for imaging. It can be used on any part of human or animal body.