Patent ID: 7875246

Claim:
A filter column module comprising: an upper column having a top opening and a protruding bottom shell, wherein the protruding bottom shell is stepped-shaped having a plurality of step surfaces, each of the step surfaces having at least one aperture configured to allow a sample to pass through the protruding bottom shell; a lower column having a support at a bottom and an opening, the opening of the lower column being stepped-shaped to correspond with and receive the protruding bottom shell of the upper column, wherein the support partially contacts the protruding bottom shell of the upper column; and a filter, placed between the protruding bottom shell of the upper column and the support of the lower column, and conforming to the stepped-shape of the protruding bottom shell, the filter being supported against the support, wherein the support has at least one hole to allow liquid or air filtered by the filter to pass through the support.