Vacuum-Type Glass Membrane Holder, stainless steel support, 25 mm, 50 ml volume, membrane filter accessories Membrane holder produced from borosilicate glass, suitable for aqueous and organic solvent filtration. Produced from borosilicate glass and available with a choice of support screen. Suitable for aqueous and organic solvent filtration. The funnel seal ensures that the sample does not bypass the membrane and that particulates are retained on the surface of the membrane. Vacuum type glass holders The sintered glass support is recommended for filtration and biological analysis. The 304 stainless steel support screen is suitable for use with proteinaceous solutions.