An instrument for extraction based molecular sample preparation and related processes is disclosed. The instrument includes a thermally conductive pressure resistant heating chamber and a thermally conductive sample cup positioned in the thermally conductive pressure resistant healing chamber for heating liquids and solids together in the thermally conductive sample cup. A liquid delivery inlet fixture in the thermally conductive pressure resistant heating chamber delivers liquids (solvent) from a supply to the thermally conductive sample cup in the thermally conductive pressure resistant heating chamber, and a chiller in liquid communication with the thermally conductive sample cup in the thermally conductive pressure resistant heating chamber receives heated liquids from the thermally conductive pressure resistant heating chamber when the chamber is opened to atmospheric pressure.