Fontana Masson Stain Kit

argentaffin stain kit fontana masson

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Part # 9105A250ml kit $424.80H




    Part 9105A
Solution A: Silver Nitrate 10%, Aqueous 250 ml
Solution B: Ammonium Hydroxide 28-30%, ACS 250 ml
Solution C: Gold Chloride 0.2%, Aqueous 250 ml
Solution D: Sodium Thiosulfate 5%, Aqueous 250 ml
Solution E: Nuclear Fast Red Stain, Kernechtrot 250 ml


COMPLIMENTARY POSITIVE CONTROL SLIDES: Enclosed with this kit are two complimentary unstained positive control slides to be used for the initial verification of staining techniques and reagents.  Verification must be documented by running one Newcomer Supply complimentary positive control slide along with your current positive control slide for the first run. Retain the second complimentary control slide for further troubleshooting, if needed.

Individual stain solutions and additional control slides may be available for purchase under separate part numbers .

Additionally Needed:

Hydrochloric Acid 5%, Aqueous Part 12086 (for acid cleaning glassware)
Xylene, ACS Part 1445
Alcohol, Ethyl Denatured, 100% Part 10841
Alcohol, Ethyl Denatured, 95% Part 10842


For storage requirements and expiration date refer to individual bottle labels.



Newcomer Supply Fontana Masson Stain Kit  procedure is used to demonstrate argentaffin substances such as melanin, argentaffin granules of carcinoid tumors, and some neurosecretory granules. This technique is not specific for melanin and argentaffin granules and other reducing substances, such as formalin pigment, will also give a positive reaction.



Fixation: Formalin 10%, Phosphate Buffered (Part 1090)

Technique:   Paraffin sections cut at 5 microns

Solutions:     All solutions manufactured by Newcomer Supply, Inc.

All Newcomer Supply Stain Kits are designed to be used with Coplin jars filled to 40 ml following the staining procedure provided below.  Some solutions in the kit may contain extra volumes.



  1. All glassware/plasticware must be acid cleaned prior to use.
  1. See Procedure Notes #1 and #2.
  1. Prepare Fontana Silver Working Solution (diamine silver) in an acid cleaned Erlenmeyer flask:
  1. Solution A:  Silver Nitrate 10%, Aqueous;     25 ml
  2. Add Solution B: Ammonium Hydroxide 28-30%, ACS drop by drop, mixing with swirling motion until solution clouds, then clears.  Use caution to not add too much Solution B: Ammonium Hydroxide 28-30%, ACS.
  3. Add more Solution A: Silver Nitrate 10%, Aqueous drop by drop until clear solution becomes slightly cloudy.
  4. Let solution stand for 2-4 hours before use.
  5. For use; after standing, filter the solution.  Then combine 20 ml of this filtered diamine silver solution with 40 ml of distilled water, 60 ml total.
  1. Deparaffinize sections thoroughly in three changes of xylene, 3 minutes each.  Hydrate through two changes each of 100% and 95% ethyl alcohols, 10 dips each.  Wash well with distilled water.
  1. See Procedure Notes #3 and #4.
  1. Immerse slides in the Fontana Silver Working Solution (Step# 2) in a 45°C to 60°C water bath for 1 hour.
  2. Check slides microscopically; remove control, rinse in warm distilled water and confirm that reaction is complete when granules are dark brown and background is colorless. Return to heated Fontana Silver Working Solution for longer incubation if indicated.
  3. Rinse well in three changes of distilled water.
  4. Immerse slides in Solution C: Gold Chloride 0.2%, Aqueous for 10 minutes.
  5. Rinse well in distilled water.
  6. Place slides in Solution D: Sodium Thiosulfate 5%, Aqueous for 5 minutes.
  7. Rinse well in distilled water.
  8. Counterstain in Solution E: Nuclear Fast Red Stain, Kernechtrot for 5 minutes.
  1. Shake solution well before use; do not filter.
  1. Rinse well in distilled water.
  1. See Procedure Note #5.
  1. Dehydrate quickly in two changes each of 95% and 100% ethyl alcohol. Clear in three changes of xylene, 10 dips each; coverslip with compatible mounting medium.  



Melanin and Argentaffin granules Black
Nuclei Pink-red



  1. Acid clean all glassware/plasticware (Part 12086) and rinse thoroughly in several changes of distilled water.  Cleaning glassware with bleach is not equivalent to acid washing.
  2. Plastic (Parts 5500, 5501), plastic-tipped or paraffin coated metal forceps must be used with any silver solution to prevent precipitation of silver salts.  No metals of any kind should be in contact with any silver solution. Only glass thermometers should be used.  
  3. Drain staining rack/slides after each step to prevent solution carry over.
  4. Do not allow sections to dry out at any point during staining procedure.
  5. Wash well after Nuclear Fast Red Stain, Kernechtrot to avoid cloudiness in dehydration steps.
  6. If using a xylene substitute, closely follow the manufacturer’s recommendations for deparaffinization and clearing steps.



  1. Sheehan, Dezna C., and Barbara B. Hrapchak. Theory and Practice of Histotechnology. 2nd ed. St. Louis: Mosby, 1980. 276-277.
  2. Luna, Lee G. Histopathologic Methods and Color Atlas of Special Stains and Tissue Artifacts. Gaitheresburg, MD: American Histolabs, 1992. 286-287.
  3. Modifications developed by Newcomer Supply Laboratory.