deparaffinointijärjestelmät

Deparaffinization is the laboratory procedure used to remove paraffin wax from histological tissue sections in order to allow subsequent staining and microscopic examination. Paraffin embedding preserves cellular morphology and allows thin slicing, but the wax blocks must be eliminated before dyes can penetrate the tissue. The process typically begins by placing the mounted slides in a series of xylene or other paraffin‑solvent baths, during which the wax dissolves. Following solvent treatment, the tissue is rehydrated through a graded series of alcohol solutions, usually descending concentrations of ethanol, and then rinsed in distilled water. Once the tissue is fully rehydrated, it is ready for antigen retrieval, immunohistochemical staining, or conventional histochemical protocols.

Deparaffinization is essential for accurate interpretation of immunohistochemical markers, such as cytokeratins, hormone receptors, or viral antigens, which otherwise would be obscured by residual wax. However, the use of strong solvents like xylene raises safety and environmental concerns, prompting laboratories to adopt alternative, less hazardous solvents or digital imaging of unstained sections. Despite these cautions, deparaffinization remains a cornerstone of modern diagnostic pathology, ensuring that cellular details are reliably visualized for clinical evaluation.