Methods for sampling, extracting, and quantitating the metabolic pools of organic acids from bacteria have been developed. The concentration of these metabolites was determined by a new gas chromatographic method that can quantitatively determine the levels of lactate, pyruvate, fumarate, succinate, malate, alpha-ketoglutarate, and citrate. Values obtained were confirmed by fluorimetric analyses of five of the individual acids. In Escherichia coli, pools range from about 1 to 5 mumol/g of dry weight, with a variation in replicate samples of 5 to 15%. Under similar conditions, these pools in Bacillus licheniformis are in the same range, although the pyruvic acid pool is significantly larger.