A safer alternative to chloroform extraction of crystal violet from
methyl green, a nasty procedure if you do not have a hood, etc, is
to purchase the methyl green from Sigma or Aldrich which is crystal
violet free, less than 0.5%.

Methyl green is described as crystal violet with a seventh methyl group
introduced by methyl chloride or methyl iodide action on the crystal
violet.  Because the methyl group has a loose attachment to the crystal
violet molecule, you end up with methyl or crystal violet as a contaminant
in methyl green.

Save your liver, bone marrow, avoid chemical waste disposal, and buy
the purified MG, it is not overly expensive.

Gayle Callis