[Histonet] Luxol fast blue for staining myelin. Validity of sources.

[John Kiernan]

This Histonet query is addressed to vendors of stains (powders and/or solutions), and to anyone who makes up luxol fast blue in the lab, avoiding the high cost of buying and transporting the flammable ready-made staining solution.

Most diagnostic labs buy ready-made staining solutions and follow a vendor's instructions, whereas research labs are likely to buy dye powders, make up their own solutions, and use them according to published books or papers. This means that the largest amounts of luxol fast blue (LFB) powder are sold to vendors of staining solutions. Am I right?

Are vendors having any problems with getting dye powders called luxol fast blue (LFB) that are consistently OK for staining myelin sheaths of axons in sections of brain, spinal cord etc?

The LFB name is informally attached to at least three dyes used as stains: LFB G (CI Solvent blue 34) and LFB ARN (CI Solvent blue37) are azo dyes, whereas LFB MBS (CI 74180, Solvent blue 38) is a copper phthalocyanine. All three have been used in similar (but not identical) published staining methods for myelin. LFB MBS is the dye most often used for this purpose, but not much is known about variation in the purity of commercial batches. It has many commercial uses and dozens of trade-names. See http://www.worlddyevariety.com/category/solvent-dyes. (It's free, unlike the Colour Index, but don't believe everything it says.)

Luxol fast blue (whichever one) may or may not be the best stain for showing myelinated axons and regions of demyelination, but it probably is the dye most used for doing this job. Is there a need for independent third-party identification, testing and certification of LFB powders? If you have encountered a bad jar of powder labeled luxol fast blue, please reply, including if possible the name on the label and the source.

The Biological Stain Commission (BSC) has never offered testing and certification for LFB as a stain for myelin, even though "luxol" dye have been in use for this job since 1953. Should third-party certification be made available for luxol fast blue? Would you submit samples for this service? For more information, see the link below.

John Kiernan
Secretary, Biological Stain Commission, Inc.
https://biologicalstaincommission.org/for-vendors/
For Vendors and Users of Stains | The Biological Stain Commission<https://biologicalstaincommission.org/for-vendors/>
Vendor FAQs: The Biological Stain Commission is a not-for-profit organization which is dedicated to the endorsement of histological materials. It is the mission of the BSC to ensure the quality of biological stains on the market that are sold by many US companies.
biologicalstaincommission.org
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