The SquameScan® 850A reduces the measuring time to a few seconds per tape strip, consequently saving costs. Additionally, the tape strip can be used for any other bioassay. The instrument is designed to indirectly measure the stratum corneum (SC) protein content on D-SQUAME® discs. Compared to the equipment required for colorimetric determination, the SquameScan® 850A has several advantages like low price, compact dimensions, and easy handling. Convenient and user friendly determination is done by measuring the optical absorption of the disc at about 850nm (infrared light). The value is displayed in % and is translated into protein content by using a simple transfer function y= a*x-b. The infrared light prevents thermal denaturing of biomolecules and influence of ambient light to the measurement result. D-SQUAME® discs are placed adhesive side up into a carrier that takes up to 10 discs and a blank. The carrier avoids contamination of tape discs during measurement and secures alignment in the SquameScan® 850A. The measured diameter is 15mm, thus covering more than half of the available disc area. So the effect of inhomogeneity of corneocyte distribution on the D-SQUAME® disc is reduced. The SquameScan® 850A is equipped with a USB port to transfer the data to a PC enabling efficient documentation and analysis of data generated.