Ultrafast Papanicolaou stain. An alternative preparation for fine needle aspiration cytology.

The objective of this study was to develop a Papanicolaou stain as fast as Diff-Quik yet with cytomorphology as exquisite as that processed by ThinPrep for the optimal evaluation of fine needle aspirates. Satisfactory results were obtained after three modifications were made: (1) rehydration of air-dried smears with normal saline, (2) use of a 4% formaldehyde/65% ethanol fixative, (3) and use of Richard-Allan Hematoxylin 2 and Cyto-stain. The first modification restored the transparency of the cells and hemolysed red blood cells, the second modification reduced the time needed for proper fixation and staining from minutes to seconds, and the third modification simplified the procedure. This 90-second protocol yields a transparent, polychromatic stain with crisp nuclear and cytoplasmic features. The cytomorphology processed by this protocol is at least equal to, if not better than, the quality of specimens prepared by ThinPrep and superior to those processed by the standard Papanicolaou procedure.