Histological Staining Techniques

Gram for bacteria
Gram, 1884.
Use a positive control section.


Gram +ve organisms - purple.
Gram -ve organisms - red.
Nuclei - red

Lillie's crystal violet
Dissolve 10g crystal violet in 100mls 95% alcohol
Dissolve 4g ammonium oxalate in 400mls distilled water
Add the two solutions together and stir the mixture for 3 hours. Filter.

Gram's iodine
Iodine 1g.
Potassium iodide - 2g
Distilled water - 300mls
Place the iodine and potassium iodide in a small quantity of the water and allow them to dissolve fully before adding the remainder of the water.

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