FSA staining (SAFELINE) is primarily used in botanical histology to differentially visualize plant cell and tissue structures. The combination of astrablue, safranin and basic fuchsin enables a multi-layered staining, with astrablue (C.I. 48048) binding to acidic cell components and safranin (C.I. 50240) and basic fuchsin (C.I. 42510) binding to basic components. The acetic acid acts as an acid that supports the staining reactions. The chemical composition of this solution ensures high staining power and excellent differentiation of cell and tissue structures. In addition, FSA staining (SAFELINE) is used in scientific laboratories for the identification of microorganisms. The application of this solution provides precise and high-contrast results that allow detailed analysis and diagnosis.