Abstract
1. An apparatus and method are described with which the oxidation of labelled substrates to (14)CO(2) by cell suspensions may be examined. 2. The use of high-specific-radioactivity substrates at low concentration together with frequent quantitative collection of CO(2) permit a more detailed analysis of the appearance of various substrate carbon atoms as CO(2) than is possible by existing techniques. 3. Typical experiments with various cell types are reported, in which pathways of glucose oxidation are examined.