Slide staining assembly and cover member

A slide staining assembly comprising:

• a mounting surface configured to retain a substrate;
• a closure body configured to retain a cover member;
• and
• a heater configured to vary a temperature of a reaction chamber,
• wherein the closure body is configured to move between a substantially closed position and an open position,
• wherein the closure body is further configured to, at the substantially closed position and in a case where both the substrate is retained by the mounting surface and also the cover member is retained by the closure body, form the reaction chamber between the substrate and the cover member, and
• wherein the closure body is further configured to, at the open position, retain a latching of tabs, extended from the closure body, latched onto the cover member in a manner in which the cover member is both removed from the substrate and is also releasably attachable to the closure body.