Improved version of the Kean partition assay for cerebroside sulfate

In the Kean method for the colorimetric determination of sulfatide (1968. J. Lipid Res. 9: 319-327), the lipid is partitioned together with a blue cationic compound between two phases formed from chloroform, methanol, and water. The blue cation enters the chloroform-rich phase only as an ion pair with the lipid. This method has been improved by the use of a new mixture of solvents in which the desired layer floats above the excess dye. The lower volatility of the new solvent system improves the reproducibility of the technique.