Exfoliative Cytology: Techniques and Staining Methods

Papanicolaou (Pap) Stain: Principle and Procedure

Exfoliative cytology is a crucial diagnostic tool in pathology, allowing the analysis of cells shed from epithelial surfaces. One of the most widely used staining techniques in this domain is the Papanicolaou stain, which enhances cellular detail and facilitates the identification of abnormalities.

Principle of Papanicolaou Stain

The Pap stain is a multichromatic staining method that highlights cellular components, providing clear differentiation of cytoplasmic and nuclear details. It relies on specific stains, including hematoxylin, Orange G, and Eosin Azure, to produce contrast among various cellular structures.

Procedure of Pap Staining

• Fixation: Cells are fixed using ethanol or other suitable agents.
• Staining:
  • Hematoxylin stains nuclear material.
  • Orange G enhances keratinized cells.
  • Eosin Azure provides cytoplasmic differentiation.
• Dehydration and Mounting: Specimen is dehydrated and mounted for microscopic examination.

This technique remains a gold standard for cervical cancer screening and other cytological assessments.