blue X-gal stocks

Patricia Foster pfoster at
Thu Dec 2 17:57:59 EST 1993

John Cooper (picard at wrote:

: We use our xgal that has turned yellow on our top agar and it works fine...

  Yellow, maybe, but blue, never.  The stuff has cleaved --
throw it out.  The solution is to keep your DMF dry by
storing it under argon passed through a column of dririte.
Make up the Xgal in small volumns and keep at -20.

Patricia L. Foster
Boston University School of Medicine
Boston, MA USA
pfoster at

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