[Babcock_Hall]

Does anyone know from experience why some manufacturers stress that their isopropyl-β-D-thiogalactopyranoside (IPTG) is free of dioxane?  How important is this?  IPTG is usually used at concentrations of 1 mM or less.  It is a non metabolizable inducer of the lactose operon.  Some claim that dioxane inhibits the growth of certain bacterial strains:
http://www.bio.net/mm/methds-reagnts/2002-January/091962.html