A method is described for the separation and isolation of tubular epithelial cells and of glomeruli from fresh dog kidney cortex. The tubular cell prepns. metabolize glucose and Krebs'' cycle intermediates at rates which lie between those reported for slices and homogenates of kidney cortex. Such oxidations are accompanied by an uptake of inorganic phosphate. Further, the tubular cell prepns. will synthesize p-aminohippuric acid from glycine and p-aminobenzoic acid at rates which approximate those obtained in kidney slices. The tubular cell prepn. also contains a phosphatase which splits glucose-6-phosphate at rates much higher than those at which the other hexose phosphates are split. This phosphatase activity is markedly inhibited by phlorhizin. This cell prepn. is discussed as a tool for the investigation of renal metabolism. The metabolic rate of the glomerular prepns. was so low as to make all attempted measurements unreliable.