Fixation Mechanism Fixatives work by cross-linking proteins and nucleic acids, which stabilizes the tissue architecture. Formaldehyde, for example, forms methylene bridges between amine groups in proteins, preserving cellular structures.
Dehydration and Clearing Dehydrating agents like ethanol remove water from tissues by creating a concentration gradient. Clearing agents then replace the dehydrating agent, making the tissue transparent and compatible with the embedding medium.
Staining Mechanism Staining agents work by binding to specific molecules within the tissue. Hematoxylin binds to acidic structures like nucleic acids, staining them blue, while eosin binds to basic structures like proteins, staining them pink.
