Is the membrane in Filter caps for Tissue culture flasks and roller bottles permeable for liquids?
No. The hydrophobic properties of the capillary pore membrane prevent liquid to stick to the membrane. The so-called water entrance pressure, a physical property of the membrane, amounts over 2.5 bars (this corresponds to a water column of 25 m). The membrane does neither wet with media nor does liquid leak through the pores even in case of accidentally dropping the flask. Functions like the high gas exchange and contamination barrier are remaining even in the described situation.
