Abstract: The present invention provides multi-well plates and column arrays in which samples (e.g., cell lysates containing nucleic acids of interest, such as RNA) can be analyzed and/or processed. In one embodiment, the microfiltration arrangement is a multilayer structure, including (i) a column plate having an array of minicolumns into which samples can be placed, (ii) a discrete filter element disposed in each minicolumn, (iii) a drip-director plate having a corresponding array of drip directors through which filtrate may egress, and (iv) a receiving-well plate having a corresponding array of receiving wells into which filtrate can flow. The invention provides multi-well microfiltration arrangements that are relatively simple to manufacture and that overcome many of the problems associated with is the prior arrangements relating to (i) cross-contamination due to wicking across a common filter sheet or (ii) individual filter elements entrapping sample constituents within substantial dead volumes.