Optimization of the skin multiple analyte profile bioanalytical method for determination of skin biomarkers from D-Squame super( registered ) tape samples

Background-purposeThis work was performed to optimize extraction conditions for D-Squame super( registered ) tape skin samples for use in the skin multiple analyte profile (SkinMAP) method, a Linco Research Corporation bead-based assay for skin analytes. The experiments were designed to help identify sources of variability during extraction that may be amenable to further control. MethodsTwo experimental designs were used to study factors influencing the extraction of skin samples from D-Squame super( registered ) tapes. Visually healthy skin samples were obtained from both female and male adult volar forearms. Factors studied in two experiments included: four surfactant (SDS) levels (0.02-0.2%), two buffer types [Citrate-phosphate buffered saline at pH 5.5, phosphate-buffered saline (PBS) at pH 7.4], two buffer volumes (1.0, 1.5 mL), two propylene glycol (PG) levels (0.1%, 1.0%), two extraction temperatures (7-10 degree C, 22-30+ degree C), two extraction times (30, 60 min), and location in sonication bath (two vectors). The response biomarkers were cortisol, fibronectin, human serum albumin, involucrin, keratin-6 and keratins 1, 10. Skin sampling sites were also evaluated as sources of variation. ResultsThere was no single set of extraction conditions in our experiments that maximized recovery of all the biomarkers. SDS level had the most consistently significant (P