Place 100 mL of 10% silver nitrate in a flask.
Add 0.5 mL of 40% sodium hydroxide and mix well.
Add drops of strong ammonium hydroxide until the precipitate just dissolves.
Tissue sample
5µ paraffin sections of neutral buffered formalin fixed tissue are suitable.
Other fixatives are likely to be satisfactory. A section adhesive is recommended.
Method
Bring sections to water via xylene and ethanol.
Place in 2% silver nitrate for 12-24 hours.
Treat with ammoniacal silver solution for 2-30 minutes.
Rinse well with distilled water.
Place in 10% formalin for 1 hour.
Wash well with tap water.
Rinse with distilled water.
Tone with acidified gold chloride solution for 1 hour.
Rinse well with distilled water.
Fix in 5% sodium thiosulphate for 10-15 minutes.
Wash well with tap water.
Dehydrate with ethanol, clear with carbol-xylene and mount with a resinous medium.
Expected results
Reticulin fibres – black
Background – grey
Notes
Ensure that the ammonium hydroxide is fresh and full strength.
Keep well stoppered when not in use. After removing the amount required immediately restopper the bottle.
Improperly made ammoniacal silver solutions can affect the quality of the impregnation.
There should be a faint, persistent opalescence, with only a faint smell of ammonia.
Toning is a variable step. Untoned sections give dark brown reticulin fibres on a paler
brown background. Many microscopists prefer to tone for about 15 seconds to produce brown-black reticulin
fibres on a pale grey-brown background. Others tone longer (a few minutes) to produce black reticulin
fibres on a grey background. Longer toning produces purple tones. Tone according to the personal preference
of the microscopist reviewing the slides.
Reference Gray, Peter. (1954) The Microtomist's Formulary and Guide. Originally published by:– The Blakiston Co. Republished by:– Robert E. Krieger Publishing Co.