Stains achieve specificity through various mechanisms:
Chemical Affinity: Certain stains have an inherent chemical affinity for specific cellular components. For example, Hematoxylin binds to negatively charged nuclear material, staining nuclei blue or purple. pH Levels: The pH of the staining solution can influence the binding of the stain. Eosin, for example, is more effective in an acidic environment, staining cytoplasmic components pink. Ion Exchange: Some stains work through ion exchange mechanisms, where ions in the stain replace ions in the tissue, leading to selective staining.
