5µ paraffin sections of neutral buffered formalin fixed tissue are suitable.
Other fixatives are likely to be satisfactory. Cryostat sections usually show brighter metachromasia.
Unmounted frozen sections may also be floated in each solution and mounted on a slide just before coverslipping.
Bring sections to water via xylene and ethanol, except for cryostat and frozen sections.
Place into methyl violet solution for 3 minutes.
Differentiate in formalin until amyloid is red and contrasts well with the tissue.
Place into sodium chloride solution for 5 minutes..
Rinse well with tap water.
Drain all water from the slide until just damp and mount with corn syrup.
Ring the coverslip to inhibit evaporation of the mounting medium and precipitation of the ingredients.
Amyloid – purple-red
Background – Blue-violet
Nuclei – Blue-violet
The sodium chloride functions to inhibit leaching of the dye into the mountant. Its action is related to that of iodine in a Gram stain.
White corn syrup (from a grocery store) is preferred.
Do the differentiation under a fume hood and be careful with the formalin.
Reference Culling C F A, Allison R T, Barr W T, (1985), p. 466. Cellular pathology technique. Ed. 4.,
Butterworths, London, England.