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D.6 Staining Smears
1. Avoid spreading smear on the edges of the slide.
2. Recommend using coated slides (SS-118).
3. Fix smears using one of the following methods:
◊ Spray fixative.
◊
Immerse in 95% alcohol for 15 to 30 minutes.
◊ Immerse in a Sacammano type fixative for 15 to 30 minutes.
4. Suggested settings:
◊
Nuclear/Htox: 3, 4, 5, 6
◊
Cytoplasmic/EU: 3, 4, 5, 6
◊
No Pre-Wash
D.7 Alternative Carbowax Removal Method
Commercially available spray fixatives have varying amounts of polyethylene glycol (carbowax). Carbowax
protects cells from air drying before fixation but can inhibit staining if not completely removed. Because the
aqueous hematoxylin reagent used in the ELITechGroup staining process is sufficient to remove the highly
water soluble carbowax under most conditions, the no Pre-Wash (default) settings are usually acceptable.
If the specimen needs to be protected from cell loss, the following method may be preferable to the lower
or higher Pre-Wash settings of the instrument:
To Remove Carbowax
1. Soak slides in 95% alcohol or 50% glycerol / 50% alcohol, for 10 to 30 minutes before staining.
Appendix E: Technical Background of Papanicolaou Staining