Utilisation of Infrared Densitometry in Stratum Corneum Research

Abstract

Tape stripping is established as a simple technique for sampling of the stratum corneum (SC) in dermatological and skin care research. It is used in a broad range of applications, e.g. to examine the changes in the biology and function of the SC in a variety of physiological and pathological skin conditions or to follow the penetration and effects of topically applied compounds. However, due to several reasons (pressure, type of tapes, skin condition, body site, ethnicity, etc.) the amount of SC removed is not constant for each individual tape stripping. Several methods of measuring of SC protein levels have been described in the literature that range from gravimetric measurements to colorimetric methods following SC protein extraction or pseudo-absorption analysis directly on the tape strippings. However, all methodologies have their own inherent problems. In this paper we briefly review the most frequently used techniques for quantification of SC on tape strippings and describe in greater detail applications using infrared (IR) densitometry with a major focus on profiling of SC serine protease levels and activities.