Several approaches exist for the mathematical modeling of cellular metabolism and its regulation, but most of them require detailed kinetic and concentration information about enzymes and various cofactors that is difficult to obtain. Taking a different tack, Bernhard Palsson and colleagues had previously reconstructed an Escherichia coli metabolic network using a stoichiometric, rather than a kinetic approach. The method relies on the application of known constraints on the integrated function of reconstructed networks and does not lead to a single solution but instead provides a domain of possible solutions that represent allowable functions of the network. On page 125, they apply their model to test the hypothesis that E. coli uses its metabolism to maximize its growth rate. They found that experimentally determined growth rates and substrate and oxygen uptake rates agreed with the a priori calculated predictions of the model, validating the in silico approach's ability to interpret and predict cellular function (see also p. 111).