MacFarland & Davenport
for Mammalian Adrenal Nerves
Materials
- MacFarland & Davenport Fixative
Material Amount Formamide 25 mL Chloral hydrate 12.5 g Ethanol, 95% 112 mL Distilled water 112 mL - Thallium nitrate, 1% aqu.
- Silver proteinate, 1% aqu.
- Oxalic acid, 0.1% aqu.
- Gold chloride, 0.2% aqu.
- Sodium thiosulphate, 5% aqu.
- Bodian developer
Material Amount Hydroquinone 1 g Sodium sulfite 5 g Distilled water 100 mL - Enhancer
Material Amount Formalin (strong, 100%) 1 mL Oxalic acid 2 g Distilled water 100 mL
Tissue Sample
15µ paraffin sections of mammalian adrenal fixed in MacFarland & Davenport’s fixative, specified above.
Protocol
- Bring sections to water via xylene and ethanol.
- Place into the thallium nitrate solution for 1-2 days.
- Wash with water.
- Place into the silver proteinate solution for 1-2 days at 37°C.
- Rinse briefly with water.
- Place into the oxalic acid solution until differentiated (7-15 seconds).
- Wash with water for 1 minute.
- Place into the Bodian developer for 3-5 minutes.
- Wash with water.
- Tone in gold chloride for 5-10 minutes.
- Wash with water for 30 seconds.
- Place in the enhancer until adequately dark (15-30 seconds).
- Rinse well with water.
- Place in the thiosulfate for 1 minute.
- Wash with water.
- Dehydrate with ethanol.
- Clear with xylene and mount with a resinous medium.
Expected Results
- Nerve fibers – black or dark brown
- Background – Lighter brown
Notes
- Steps 13-15, the post enhancer treatment with thiosulfate, was not explicitly given in the instructions. However, the thiosulfate solution was specified as one of the solutions, so presumably was intended for use. It is likely that the omission was unintentional. Its placement in the method is the most likely, but some trials both in duration and placement may be required.
- Formamide is also known as methenamide, formula HCONH2.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Gray, Peter. (1954)
The Microtomist’s Formulary and Guide.
Originally published by: The Blakiston Co.
Republished by: Robert E. Krieger Publishing Co.
Citing:
MacFarland and Davenport, (1941)
Stain Technology, v. 16, p. 53
Geneva, NY, USA
