AN IMPROVED CATHODE FOR THE MEASUREMENT OF PHOTOSYNTHETIC OXYGEN EVOLUTION BY ISOLATED CHLOROPLASTS

Abstract

S ummary The construction, operation and calibration of an improved form of a Clark oxygen electrode are described in detail. The electrode shows a rapid response (1–5 seconds) to change in oxygen concentration and is capable of measuring rates of oxygen evolution (or uptake) of up to 4 μmoles oxygen per minute. The use of a pair of electrodes to measure the oxygen evolution of choloroplasts at high intensity of illumination is described.