Purification of Alcian Blue

Commercially available Alcian Blue (#E10350) contains about 49% dye; the remaining constituents are boric acid, sulphates, dextrin, and other unknown organic substances. It can be purified by the following method, presented by McAuliffe. W.G. McAuliffe (1983) - A Note on the Purification of Alcian Blue. Stain Technology, 58, pg 374.

• One gram of Alcian Blue is placed in a flask to which is added 100ml of 9:1 mixture of acetone and distilled water.
• This mixture is stirred for 1 hour and then filtered through No. 2 filter paper. Small quantities of additional acetone are used to wash the dye from the flask and down the side of the filter paper.
• The filtrate has a faint yellow-green color. The residue is recovered from the filter paper and dried.
• Small quantities of the dye should be purified as they are needed.

The above method yields Alcian Blue containing about 78.7-83.5% dye, depending on the commercial source.

Reference:
Hayat, M. A. (Ed.). (1989). Principles and Techniques of Electron Microscopy. Third