Filtering particles from blood or other media

Abstract

A filter element and method for retaining particles of a medium, for example rare cells of blood. The filter element includes at least one opening that has an elongate cross section and/or a cross section that decreases in a flow direction. The filter element may be bordered by a transparent wall. The filter element may be provided with a plurality of elongate openings of a stepwise decreasing cross section that are arranged on a common transparent slide. The filter element permits high flow rates to be realized throughout the filtering process and the retained particles are immediately ready for visual inspection without a need for a further transfer.

Dependencies are inferred from the claim text.