US Patent 7357042 Filter contamination control device

A biological specimen filter, for use in a biological specimen collection and transfer system having a vacuum source, comprises a tubular body having an exterior surface, an interior chamber, a first end configured to couple to the vacuum source, and a second end having an opening in communication with the chamber, and a fluid trap extending around at least a portion of a circumference of the exterior surface of the tubular body and sized and shaped to catch fluid flowing along the exterior surface as the tubular body is inverted from a first position, in which the opening is submerged in a fluid source, to a second position, in which the opening is removed from the fluid source.