PVDF, or PolyVinyliDine Fluoride, a membrane used making a Western Blot, binds and immobilizes proteins. PVDF is widely used as an alternative to Nitrocellulose because it is sturdier, and in addition can be "stripped" of antibodies and subsequent immunoblots can be performed. Unlike nitrocellulose, PVDF must be wet in 100% methanol before using.