Simulated Z-Scores. Two possible glucose label patterns show different strengths in evaluating different parts of the network. Brighter colors indicate more easily determined fluxes. a) [1-13C] glucose Z-scores illustrates flux determinability with 100% [1-13C] glucose. b) [6-13C] glucose Z-scores shows the same network evaluated with [6-13C] glucose. It is observed, for example, that [6-13C] glucose is predicted to elucidate the pentose phosphate pathway more easily, while [1-13C] glucose better elucidates the glyoxylate shunt.