9 SCIENTIFIC APPARATUS AND INSTRUMENTS; APPARATUS FOR DIRECTING A HYDRODYNAMICALLY FOCUSED FLOW OF LIQUID OVER A SURFACE FOR MOLECULAR INTERACTION THEREWITH; LABORATORY EQUIPMENT; APPARATUS FOR SCREENING SAMPLES, DETECTING THE PRESENCE OF ANALYSTS IN SAMPLES, OR IDENTIFYING SAMPLE TYPES; EQUIPMENT FOR MAKING ARRAYS; APPARATUS FOR DETECTING OR MEASURING THE EFFECT OF SUBSTANCES ON BIOLOGICAL CELLS FOR SCIENTIFIC PURPOSES