Diagnostic Cytology: Staining Techniques and Interpretation

Papanicolaou (Pap) Stain: Methodology and Clinical Applications

The Papanicolaou stain, commonly known as the Pap stain, is a vital staining technique in cytology, primarily used for screening cervical cancer. Developed by Dr. George Papanicolaou, this stain differentiates cellular components, enabling precise interpretation of cytological specimens.

Methodology

Fixation: Cells are fixed using alcohol-based solutions to preserve morphology.
Staining Process: The procedure involves sequential staining using hematoxylin, orange G, and EA (Eosin Azure).
Microscopic Examination: Stained slides are analyzed under a microscope to assess cellular abnormalities.

Clinical Applications

Pap staining is instrumental in diagnosing cervical cancer, detecting precancerous lesions, and evaluating infections. Its application extends to respiratory, urinary, and gastrointestinal cytology.

Interpretation

The stain highlights nuclear and cytoplasmic characteristics, aiding pathologists in identifying dysplastic and neoplastic changes. Normal cells appear well-defined, whereas atypical cells exhibit irregular morphology.