Congo Red Stain Set, Puchtler, Amyloid
(use: Mod. of Bennhold; reduces background birefringence.)
- Solution A: Sodium Hydroxide 1%, Aqueous 25ml or 50ml
- Solution B: Congo Red Stain, Alcoholic 250ml or 500ml
SET INCLUDES:
Part 1037A | Part 1037B | ||
Solution A: | Sodium Hydroxide 1%, Aqueous | 25 ml | 50 ml |
Solution B: | Congo Red Stain, Alcoholic | 250 ml | 500 ml |
Additionally Needed:
Amyloid, Animal Control Slides OR Amyloid Control Slides |
Part 4031 OR Part 4030 |
Xylene, ACS | Part 1445 |
Alcohol, Ethyl Denatured, 100% | Part 10841 |
Alcohol, Ethyl Denatured, 95% | Part 10842 |
Hematoxylin Stain, Harris Modified | Part 1201 |
For storage requirements and expiration date refer to individual product labels.
APPLICATION:
Newcomer Supply Congo Red Stain Set, Puchtler, Amyloid is used in identifying extraneous protein deposits in amyloidosis. The use of polarizing lenses is essential for visualizing amyloid positive areas or to confirm negativity.
METHOD:
Fixation: Formalin 10%, Phosphate Buffered (Part 1090)
Technique: Paraffin sections cut at 8 microns
Solutions: All solutions are manufactured by Newcomer Supply, Inc.
All Newcomer Supply Stain Sets are designed to be used with Coplin jars filled to 40 ml following the provided staining procedure. Some solutions in the set may contain extra volumes.
PRESTAINING PREPARATION:
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- If necessary, heat dry tissue sections/slides in oven.
- Prepare fresh Congo Red Working Stain Solution; combine and mix well.
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- Solution B: Congo Red Stain, Alcoholic 40 ml
- Solution A: Sodium Hydroxide 1%, Aqueous 0.4 ml
- See Procedure Note #1.
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STAINING PROCEDURE:
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- 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.
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- See Procedure Notes #2 and #3.
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- Stain in Hematoxylin Stain, Harris Modified (Part 1201) for 30 seconds to 1 minute.
- Wash in running tap water for 1 minute; rinse in distilled water.
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- Do not differentiate or use a bluing agent.
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- Place in 95% ethyl alcohol; 1-2 dips.
- Stain in fresh Congo Red Working Stain Solution (Step #2) for 20-30 minutes.
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- See Procedure Note #4.
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- Dehydrate quickly in two changes each of 95% and 100% ethyl alcohol; 10 dips each. Clear in three changes of xylene, 10 dips each; coverslip with compatible mounting medium.
- 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.
RESULTS:
Light Field Microscopy: | ||
Amyloid | Pink to red | |
Nuclei | Blue | |
Polarized Light: | ||
Amyloid fluorescence | Apple green |
PROCEDURE NOTES:
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- Solution B: Congo Red Stain Alcoholic is a saturated solution and dye may precipitate, which can be filtered out.
- Drain slides after each step to prevent solution carry over.
- Do not allow sections to dry out at any point during procedure.
- Exposure in Congo Red Working Stain Solution can be extended up to 50 minutes to increase staining intensity.
- For optimal results sections should be cut at 8 microns to provide more intense staining and allow smaller amyloid deposits to be identified.
- If using a xylene substitute, follow manufacturer’s recommendation for deparaffinization and clearing steps.
REFERENCES:
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- Carson, Freida L. and Christa Hladik Cappellano. Histotechnology: A Self-instructional Text. 4th ed. Chicago: ASCP Press, 2015. 154-155.
- Churukian, Charles. “Improved Puchtler’s Congo Red Method for Demonstrating Amyloid.” The Journal of Histotechnology 23.2 (2000): 139-141.
- Sheehan, Dezna C. and Barbara B. Hrapchak. Theory and Practice of Histotechnology. 2nd ed. St. Louis: Mosby, 1980. 177-178.
- Modifications developed by Newcomer Supply Laboratory.