Following the application of Schiff's reagent the excess must be removed somehow. In the past it was thought that rinsing with water could cause recolouration of the Schiff's reagent, which would then stain the tissue giving the appearance of positive staining. Sulphite rinses were developed to inhibit recolouration, by rinsing off Schiff's reagent with the solvent used to make it.
It is now known this is not necessary and, provided the sections do not stay in recoloured Schiff reagent for any length of time, non specific staining does not take place. It is common practice now to simply wash in running tap water for about 20 minutes.
|Solution A||Solution B|
|Sodium metabisulphite||5 g||Hydrochloric acid, conc||1 mL|
|Distilled water||100 mL||Distilled water||1 L|
|Solution A||1 volume||Potassium metabisulphite
may also be used in
|Solution B||9 volumes|
|Make fresh daily.|
Lillie, R.D., (1954)
Histopathologic technique and practical histochemistry Ed.2
Blakiston, New York, USA.