Rectum colon mucicarmine.

FIXATION:        Carnoy’s or alcoholic-formalin.  10% buffered neutral formalin may be used.

TECHNIQUE:        Paraffin sections cut at 5 μm.

SOLUTIONS:

Weigert’s Iron Hematoxylin

(See Southgate’s mucicarmine method)

Carmine Solution (Stock)

Carmine, C.I. 75470 ------------------------------------------------------------                2.0 gm.

Potassium carbonate ------------------------------------------------------------                1.0 gm

Potassium chloride --------------------------------------------------------------                5.0 gm

Distilled water -------------------------------------------------------------------        60.0 ml

       Boil gently and cautiously for 5 minutes.  When cool add 20 ml

       of 28% ammonium hydroxide.  Store in the refrigerator.

Carmine Solution (Working)

Carmine solution (stock) -------------------------------------------------------                10.0 ml

Ammonium hydroxide, 28% --------------------------------------------------                15.0 ml

Methyl alcohol ------------------------------------------------------------------                15.0 ml

Differentiating Solution

Alcohol, absolute ----------------------------------------------------------------        20.0 ml

Methyl alcohol -------------------------------------------------------------------        10.0 ml

Distilled water -------------------------------------------------------------------        25.0 ml

• Two slides are required.  One of the slides is diastase digested (see PAS-diastase method) and then both slides are stained.

1. Deparaffinize and hydrate to distilled water.
2. Weigert’s iron hematoxylin for 1 minute.
3. Wash briefly in running water.
4. Decolorize with 0.5% hydrochloric acid in 70% alcohol for 10 seconds.
5. Wash in running water for 5 minutes.
6. Rinse in distilled water.
7. Working carmine solution for 30 minutes.
8. Place in differentiating solution for 3 seconds.
9. Rinse quickly in 70% alcohol.
10. Dehydrate in graded alcohols.
11. Clear in xylene, three or four changes.
12. Mount with synthetic resin.

Staining attributed to glycogen is selectively eliminated in the diastase digested slide, but will be stained pink to red in the undigested slide.

Mallory, F.B.:  Pathological Technique, New York, Hafner Publishing Co., 1961, pp. 126-128.