Silicone stoppers for airtight reactions?

[Mary Elyse Lucero]

	I am preparing stock solutions for reagents to be used in a
reaction with an oxygen sensitive enzyme.  I know that black rubber or
butyl rubber stoppers are usually used for keeping solutions anaerobic. 
Does anyone know if silicone stoppers will work for this purpose?  How
permeable to oxygen is silicone?


Thanks,

Mary Lucero
malucero at nmsu.edu