Comparison of origin of metabolic intermediates in E. coli MG1655 Δ arcA Δ iclR and E. coli BL21 (DE3) under glucose abundant conditions. Standard deviations are calculated on different samples originating from different cultivations. The serine through EMP and the pyruvate through ED results were obtained from experiments using 50% 1-13C glucose and 50% naturally labeled glucose. To determine the remaining values a mixture of 20% U-13C glucose and 0 naturally labeled glucose was used. To determine the fractions resulting in the formation of OAA a Monte-Carlo approach was applied.