I found the discussion interesting on cleaning up methyl green with
chloroform, and the answer one used acetone to clean up methyl green, another
used chloroform which I think means two different things.

In the good old days, and I know a bunch out there in Histoland who have
done this, we purified or cleaned up methyl green (extracted methyl violet, a
dye contaminant in the methyl green from mfg process) by making an aqueous
methyl green solution, put into a separating funnel, add chloroform, shake
up this mixture, let stand and decant off bottom the layer of chloroform
and methyl violet. This was done approx 3 X, until chloroform was clear,
indicating pure methyl green in aqueous portion above.  No chloroform
was ever used with methyl green staining.

Another said they used acetone to clean up methyl green which meant they
used the acetone post staining, in dehydration process before clearing.

If you are still doing chloroform extraction, you may want to look into
purchasing methyl violet free methyl green,  which I think is available from
both Sigma and Roboz (now some other name) under a German name, sorry at home
and not by my stain supply!

Sort of miss the old way at times, made me feel very chemist-like!  But I think
my liver and bone marrow is safer.

Gayle Callis