Abstract
Bovine serum albumin in the preparative medium enabled the isolation from etiolated cotton seedling hypocotyls of subcellular paritcles which would effectively carry out oxidative phosphorylation with succinate as the substrate. Its action was probably that of neutralizing an unidentified toxic material found in cotton tissue. Albumin was a critical additive in grinding and washing steps but not in the reaction -mixture. In general, phosphorylation was decreased more than oxidation was when albumin concentrations were decreased. Mortar preparations were superior to blender preparations under comparable conditions. Other factors considered produced conventional results.