Aldehyde Toluidine Blue
for Mast Cells
|Hydrochloric acid, conc
|Dissolve the dye in the ethanol. Add paraldehyde and acid.|
Ripen one week at room temperature. Store at room temperature.
Filter before use. Stable for a year or longer.
5µ paraffin sections of neutral buffered formalin fixed tissue are suitable.
Other fixatives are likely to be satisfactory.
- Bring sections to water via xylene and ethanol.
- Rinse with 70% ethanol.
- Place in solution A for 1 hour.
- Wash off excess stain with 70% ethanol.
- Rinse well with tap water.
- Counterstain with nuclear fast red-tartrazine.
- Dehydrate with ethanol, clear with xylene and mount with a resinous medium.
- Mast cell granules – deep blue
- Nuclei – red
- Background – yellow
- The staining solution is a modification of Gomori's aldehyde fuchsin
using toluidine blue instead of basic fuchsin.
- Staining time may need to be increased as the solution ages (up to 2 hours). If staining takes longer than 2 hours, prepare a new solution.
- Elastic fibres are unstained, likely because basic fuchsin can form
and toluidine blue generally does not.
- Mucins are stained very pale blue.
- Different samples of this dye may vary in effectiveness.
If a sample gives pale staining, try one from another vendor.
Toluidine blue from Fisher Scientific was used to develop the method.
Llewellyn, B. D., unpublished.
Last updated January 2019