Abstract: A cover member for a substrate supporting a biological sample comprises first and second opposing ends, first and second opposing surfaces, a void in the second surface which, when juxtaposed with a substrate, forms a chamber, and a fluid inlet toward the first end and in fluid communication with the void. The void is bounded by void walls having one or more contoured regions for enhancing fluid movement within the chamber. A treatment module for a biological sample comprises the cover member, a support surface for a substrate bearing the biological sample and clamp means operable to releasably retain the cover member in juxtaposition with the substrate for an incubation period. A method for incubating the biological sample with one or more reagents uses the cover member.

Abstract: A sample processing assembly for treatment of a sample on a substrate includes a mounting surface for the substrate and a closure body configured to releasably retain a cover member. The closure body is movable between an open position and a substantially closed position. When a substrate is placed in the assembly and the closure body is in the substantially closed position while retaining a cover member, a reaction chamber is formed for processing a sample. A cover member for use with the sample processing assembly is also provided.