Used in dermatological research to quantify levels of human epidermal keratin in cell cultures, tissue extracts, or biological fluids. Helps assess skin barrier function, epithelial cell differentiation, and wound healing processes. Commonly applied in studies related to skin diseases such as psoriasis, eczema, and ichthyosis. Also utilized in cosmetic research to evaluate the effects of topical agents on keratin expression and skin health. Provides a reliable, sensitive method for detecting changes in keratin levels in response to treatments or environmental factors.