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 Test plates for chemical or biochemical analysis which contain a plurality of individual wells or reaction chambers are well known laboratory tools. Such devices have been employed for a broad variety of purposes and assays, and are exemplified in U.S. Pat. Nos. 4,734,192 and 5,009,780, for example. Microporous membrane filters and filtration devices containing the same have become especially useful with many of the recently developed cell and tissue culture techniques and assays, especially in the fields of virology and immunology. Multiwell plates, used in assays, often use a vacuum applied to the underside of the membrane as the driving force to generate fluid flow through the membrane.
 Typically, a 96-well filtration plate is used to conduct multiple assays simultaneously. In the case of multiwell products, there is a need to deal with liquid collection, removal and recovery in an effective manner. In particular, high throughput applications, such as DNA sequencing, PCR product cleanup, plasmid preparation, drug screening and sample binding and elution require products that perform consistently and effectively. If droplets are allowed to remain in proximity to the purified sample for longer than necessary, a variety of deleterious effects may result, including possible contamination of purified sample.
 One such filtration device commercially available from Millipore Corporation under the name “Multiscreen” is a 96-well filter plate that can be loaded with adsorptive materials, filter materials or particles. The Multiscreen underdrain has a phobic spray applied in order to facilitate the release of droplets. More specifically, the MultiScreen includes an underdrain system that includes a spout for filtrate collection. This spout not only directs the droplets but also controls the size of the drops. Without the underdrain system, very large drops form across the entire underside of the membrane. The drop volume that can remain without such an underdrain is much larger than with such an underdrain. The spout is hydrophobically treated to enhance droplet release for quantitative collection.
 It would therefore be desirable to provide an effective means for liquid collection in sample preparation devices such as multiwell arrays.
 It would also be desirable to provide an effective means for removal of filtrate droplets from the underside of a membrane without requiring the addition of an underdrain system.
 The problems of the prior art have been overcome by the present invention, which provides a device and method for removal of liquid from the downstream side of a membrane or a well, such as a well of a multiwell plate. More specifically, the present invention is directed to a wicking structure, which channels droplets of liquid away from a membrane or well, preferably a plurality of wells. In the preferred embodiment, the wicking structure is placed in a vacuum manifold in close proximity to the underside of the membrane or it can be an integral part of the manifold.
 Since the presence of the wicking structure below the downstream side of the membrane effectively removes droplets of filtrate, contaminants in these droplets are channeled away from the membrane and are less likely to re-contaminate the sample through diffusion or osmotic forces, for example. Contamination of associated equipment, such as the robotic deck that the samples are processed on, is also less likely or eliminated. In addition, a wicking structure makes successive washes of samples on the upstream side of the membrane more efficient since contaminants are directed away from the underside of the membrane. The wicking structure is preferably used where quantitative collection of filtrate is not desired.
 Turning first to
 A liquid droplet
 The wicking structure
 Where the wicking structure or matrix
 The configuration of the wicking structure
 In order to facilitate transfer of the droplet of filtrate from the surface of the membrane
 Regardless of the particular wicking structure used, the wicking structure functions to remove droplets formed from a plurality of sample wells into a single or common collection chamber. Segregation of the droplets forming from each well, and thus quantitative collection of the filtrate, is not required; droplets from all of the wells can be combined and collected together. The particular configuration of the common collection chamber is not particularly limited.