Eosin 2%, alcoholic 70%, is an eosin solution used in histology and cytology for selective staining of basic structures such as proteins, especially cytoplasm and extracellular matrix. The solution consists of a concentration of 2% eosin and 70% alcohol, making it suitable for various applications where moderate staining is desired.

The alcohol content in this solution acts as a solvent and allows faster diffusion of the dye into the tissue, resulting in a shorter staining time. The faster diffusion of the alcoholic solution allows for better penetration of the dye into the tissue and more even distribution of the dye. In addition, the alcohol content helps to reduce cell swelling, resulting in sharper visualization of structures.

The 2% eosin concentration in this solution provides a balanced stain that is well suited for the detection of cellular and extracellular structures in histological sections. The intensity of the staining can be further optimized by adjusting the exposure time. The alcoholic eosin solution is suitable for routine staining as well as for special staining techniques where stronger staining is desired.