Papanicolaou stain

Papanicolaou stain, abbreviated Pap stain, is a standard stain used in cytopathology. It is a modified H&E stain.

General

• Can be thought of as the H&E of cytopathology.
  • It is a modified H&E stain.
• Specimens are fixed in ethanol.
• Good for seeing nuclear detail.
• Out-of-focus cytoplasm is translucent; allows one to focus overlapped cells in different planes.

Use

• Cytopathology.

Interpretation

• Blue/purple = nucleus.
• Green/pink = cytoplasm.
• Orange = keratin.

Image

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  Pap stain - urine cytology (WC)

See also

• Stains.