Alcian Blue Solution at pH 1.0 is primarily used in histology and cytology for the selective staining of acidic mucopolysaccharides and glycosaminoglycans in tissue sections. At this low pH, the dye specifically binds to carboxyl and sulfate groups present in these acidic macromolecules, allowing for clear differentiation of tissue components such as hyaluronic acid, chondroitin sulfate, and other sulfated mucins. It is commonly employed in the identification and evaluation of mucin-producing cells in epithelial tissues, particularly in gastrointestinal and respiratory tracts. The stain is also used in combination with other dyes, such as periodic acid-Schiff (PAS), to distinguish between neutral and acidic mucins in a technique known as the Alcian Blue–PAS method. In research and diagnostic pathology, this solution aids in the study of connective tissue disorders, cartilage composition, and tumor classification based on mucin expression patterns. Its high specificity at pH 1.0 makes it a valuable tool for visualizing sulfated glycosaminoglycans in cartilage and other extracellular matrices.