B-5 Fixative Modified, Zinc Chloride

Newcomer Supply Beaker

      • Shelf Life is 2 years from date of manufacture.

Product Options:

1 - 5:
Part # 1015A 1 L $50.50
6 or more:
Part # 1015A 1 L $45.00
Part # 1015C 1 gal $129.10


1 Liter 6 X 1 Liter 1 Gallon
B-5 Fixative Modified, Zinc Chloride Part 1015A Part 1015A Part 1015C


Additionally Needed:

Formaldehyde 37-40%, ACS Part 1089


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



Newcomer Supply B-5 Fixative Modified, Zinc Chloride is a safe mercury free alternative to the classic B-5 fixative.  It is the fixative of choice for bone marrow, lymph nodes, spleen and other hematopoietic tissues, and provides clear nuclear detail while preserving immunohistochemical (IHC) staining.



Fixation Recommendations:

  • Bone Marrow Clot: Minimum of 2 hours.
  • Bone Marrow Biopsy: Minimum of 3 hours.
  • Lymph Nodes and Small Biopsies: Minimum of 4 hours.
  • Small nodes (5 mm or less) should be halved.
  • Larger nodes, dissected so no piece is thicker than 3 mm.

Solutions: All solutions are manufactured by Newcomer Supply, Inc.



    1. B-5 Fixative Modified, Zinc Chloride Working Solution:
        1. B-5 Fixative Modified, Zinc Chloride 50 ml
        2. Formaldehyde 37-40%, ACS                   5 ml
    2. Combine solutions directly before use. Fix tissue in fresh 10:1 working solution a minimum of 2 to 4 hours.
    3. Hold tissue specimens in B-5 Fixative Modified, Zinc Chloride Working Solution until ready to process or a maximum of 72 hours.
        1. See Procedure Note #1.
    4. Wash fixed tissue in running tap water to remove residual zinc chloride.
    5. Place on tissue processor in Formalin 10%, Phosphate Buffered (Part 1090) fixation step.



    1. After maximum fixation of 72 hours, transfer B-5 fixed wet tissue to 70% Ethyl Alcohol (Part 10844) for long-term storage.
    2. Nitric acid is not recommended as a decalcification agent following fixation in B-5 Fixative Modified, Zinc Chloride.
    3. Neutralize B-5 Fixative Modified, Zinc Chloride with sodium carbonate or sodium bicarbonate to precipitate zinc at pH 7.0-8.0.
        1. Approximately 100 grams of sodium bicarbonate will neutralize/precipitate zinc from 1 liter of B-5 Fixative Modified, Zinc Chloride.



    1. Bancroft, John D., and Marilyn Gamble. Theory and Practice of Histological Techniques. 6th ed. Oxford: Churchill Livingstone Elsevier, 2008. 69.
    2. Carson, Freida L., and Christa Hladik Cappellano. Histotechnology: A Self-Instructional Text. 4th ed. Chicago: ASCP Press, 2015. 19-20.
    3. Dapson, Janet Crookham, and Richard Dapson. Hazardous Materials in the Histopathology Laboratory: Regulations, Risks, Handling, and Disposal. 4th ed. Battle Creek, MI: Anatech, 2005. 148-149, 279.
    4. Modifications developed by Newcomer Supply Laboratory.