Sections should appear clear after the deparaffinization step. If white patches are present, they indicate that the slides were not completely dried of water and/or deparaffinized.
Possible Causes:
- Insufficient drying time
- Insufficient time in deparaffinization solvent (xylene) or solvent substitute
Remedy:
- Return the slides to the oven or place them in 100% alcohol
- 2–3 changes of deparaffinization solvent (xylene) or solvent substitute over 10 minutes should be sufficient time to remove all of the paraffin
